M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme ARITHMETIC UNIT1. CARDINAL AND ORDINAL NUMBERS. Cardinals for counting. How do you read and write cardinal numbers? Ordinals for arranging. How do you read and write ordinal numbers? Some exceptions. UNIT2. THE FOUR OPERATIONS ON NUMBERS. The four basic operations: Addition, subtraction, multiplication and division. How do you read arithmetic expressions? Review some different methods of multiplication and division. UNIT3. BIG NUMBERS. The place value of numbers. Rounding big numbers. UNIT4. POWERS. Power, index and base. The squares and the cubes of the first natural numbers. Numbers in expanded form and in index form. General rules of powers. 1 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme UNIT5. MULTIPLES AND FACTORS. Multiples. Factors. Prime numbers. Test of divisibility. The lowest common multiple. The highest common divisor. UNIT6. INTEGERS. What is an integer? Operating with integers. UNIT7. DECIMAL NUMBERS. How do you read decimal numbers? The place value of a number. Writing in order. Operating with decimals. UNIT8. FRACTIONS, DECIMALS AND PERCENTAGES. What is a fraction? How do you read fractions? Different types of fractions. Fractions and decimals. A fraction like an operator. Equivalent fractions. Comparing fractions. 2 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme Fractions, decimals and percentages. Ratio and proportion. Adding and subtracting fractions. Multiplying fractions. Dividing fractions. Combined operations with fractions. Fractions with the calculator. UNIT9. SPECIAL NUMBER SEQUENCES. Even and odd numbers. Square and cube numbers. Triangle numbers. UNIT10. THE REAL NUMBER. Rational numbers. Irrational numbers. Square root. Cube root. The n-th root. The rules of Operating with roots. 3 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme UNIT 1.CARDINAL AND ORDINAL NUMBERS. Los números desde el punto de vista gramatical son adjetivos numerales y pueden aparecer de dos formas, como números cardinales y como números ordinales. A) CARDINAL NUMBERS (números para contar / counting numbers /numbers used for counting / to count) NUMBERS CARDINALS 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 30 40 50 60 70 80 90 100 101 1000 1001 1000000 Nought, zero one two three four five six seven eight nine ten eleven twelve thirteen fourteen fifteen sixteen seventeen eighteen nineteen twenty twenty-one thirty forty fifty sixty seventy eighty ninety one hundred one hundred and one one thousand one thousand and one one million 4 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme OBSERVACIONES sobre números cardinales: Las unidades se separan de las decenas por un guión. 25 67 31 En un número de tres cifras one hundred, two hundred, van siempre seguidos de and. 123 237 986 three thousand and eighty-one Los números de cuatro cifras, especialmente las fechas pueden leerse por parejas 1975 3786 2007 one thousand three hundred and fifty Si el lugar de las centenas lo ocupa un cero, los millares van seguidos de and. 3081 4098 1072 one hundred and twenty-three Los millares no se unen a las centenas ni con guión, ni con and, ni con coma. 1350 4567 5281 twenty-five nineteen seventy-five Los números de cuatro cifras terminados en dos ceros, pueden leerse con las dos primeras cifras seguidas de hundred 2500 7800 twenty-five hundred 5 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme En lenguaje coloquial, hundred, thousand and million suelen ir precedidos de a en lugar de one a hundred a thousand a million Hundred, thousand and million, cuando van precedidos de otro número o determinante numeral, o sea, cuando funcionan como adjetivos, no llevan s final en el plural En cambio si funcionan como sustantivos si termina en s el plural. Doscientos dolares Miles de pajaros Varios cientos de libras Tres millones de euros Two hundred dollars Thousands of birds En Inglés, se utiliza una coma ó un espacio para marcar los millares (nunca un punto como nosotros) 25,670 25 670 El cero: 0 nought zero o nothing nil love mathematical digits point zero, zero degrees telephone numbers coloquial In football In tennis 6 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme B) ORDINAL NUMBERS (números para ordenar/ arranging numbers / numbers used for arranging / to arrange) NUMBERS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 30 40 50 60 70 80 90 100 CARDINAL NUMBERS ORDINAL NUMBERS First Second Third Fourth Fifth Sixth Seventh Eighth Ninth Tenth Eleventh Twelfth Thirteenth Fourteenth Fifteenth Sixteenth Seventeenth Eighteenth Nineteenth Twentieth Twenty-first Thirtieth Fourtieth Fiftieth Sixtieth Seventieth Eightieth Ninetieth One hundredth 101 One hundred and first 1000 One thousandth 1001 One thousand and first 1000000 One millionth 7 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme OBSERVACIONES sobre números ordinales: 1576 Los números ordinales se forman a partir del correspondiente cardinal, con sólo añadir la terminación th a las unidades. One thousand five hundred and seventy-six One thousand five hundred and seventy-sixth 29 341 1002308 Excepto los tres primeros ordinales, que son totalmente irregulares. 1 2 3 5º 8º 9º 12º 20º,30º,40º,… One Two Three first No obstante observa las siguientes modificaciones gráficas. Cambio de ve por f Se añade sólo h por terminar en t Pérdida de la e final Cambio de ve por f + th Cambio de y por ie + th fifth Los números ordinales se abrevian añadiendo al número cardinal correspondiente las dos últimas letras de dicho ordinal. 1º 2º 3º 4º 18º 1st 2nd 3rd 4th 18th 8 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme Situaciones en las que se utilizan números ordinales FECHAS TITULOS PREMIOS SIGLOS CLASIFICACIONES 1st April, 1st of April, April the 1st, April 1st Isabel II Elisabeth II Elisabeth the second The first prize, the 2nd prize, …… 21st century, 18th century, …. The 4th position El primero y el último EL PRIMERO THE FIRST EL ÚLTIMO THE LAST EL SEGUNDO THE SECOND EL PENÚLTIMO THE SECOND LAST EL TERCERO THE THIRD EL ANTEPENÚLTIMO THE THIRD LAST 9 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme UNIT 2. THE FOUR BASIC OPERATIONS ON NUMBER Do you know the four basic operations on numbers? OPERATION Addition Subtraction Multiplication Division MEANING SYMBOL To add, To collect, To combine, To put toguether + To subtract, To take away. It’s the inverse of addition To multiply, To add some copies of the same number. It’s a repeated addition. To divide, To share in equal portions. It’s the inverse of multiplication. - × ÷ EXAMPLE Plus Minus Multiplied by or Times Divided by How do you read? ARITHMETIC SYMBOLS Equals, = Is equal to, Is Plus + - Minus IN FIGURES IN WORDS 6 9 15 ……………………………………..... 17 35 52 ............................................................. 10 5 5 ……………………………………..... 23 8 15 ............................................................. Times or Multiplied by 5 6 30 ……………………………………..... 12 5 60 ............................................................. Divided by 40 5 8 ………………………………………. 72 9 8 ............................................................. 10 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme You need to be able to add and subtract numbers (one digit numbers, two digit numbers, three digit numbers, ...): In a addition, don’t forget: To line up the unit digits. To write first the number with more digits. To start from the right. EXERCISE: 456 379 15 1. Calculate the result using the columnar addition. 2. Circle in green colour the addends. 3. Circle in red colour the sum or total. In a subtraction, don’t forget: To line up the units. To write first the greatest number. To start from the right. 1. Work out the solution, using the columnar subtraction: 1. Tick in blue colour the minuend . 2. Tick in red colour the subtrahend. 3. Tick in green colour the difference. 11 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme You need to know the multiplication tables up 10 1 0 , they are essential for both multiplication and division: You need to do perfectly short multiplication and short division. (The multiplier and the divisor are one digit number). EXERCISE: There are some different methods for long multiplication and long division. EXAMPLES: 1. Small tins of fried tomato weigh 157 grams. How much do 35 tins weigh? The question is 157 35 . We can solve it using different methods: 12 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme 1. STANDARD COLUMN METHOD. STEP 1 Write down the multiplication lining up the units. (Write first the number with more digits). STEP 2 Split the second number in their units and tens. STEP 3 Multiply 157 by the units (5). STEP 4 Multiply 157 by the tens (30). STEP 5 Finally add both answers to get the total. The answer is 5,495 2. BOX METHOD. STEP 1 Draw a box 3 squares by 2 squares (it is a multiplication of 3 digits by 2 digits). Split the numbers into their hundreds, tens and units along the top and down the left-hand side. STEP 2 Multiply the numbers at the top and the numbers at the side and put each answer in each box. STEP 3 Take the number from the boxes and write them down, lining up the units. Finally add them together. The answer is 5,495 13 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme 3. CHINESE MULTIPLICATION. (Observa el ejemplo e intenta describir en español los tres pasos) STEP 1 STEP 2 STEP 3 The answer is 5,495 4. RUSSIAN METHOD. Look at the video and take notes. 14 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme 5. EGYPCIAN METHOD. Look at the video and take notes. 6. SIMPLE GRAPHICAL METHOD. Pay attention carefully to the video and take notes. 15 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme 2. We are 806 students in my school distributed in 31 class-rooms. How many pupils are in each group? The question is 806 31 . Do this by the METHOD SIMILAR TO SHORT DIVISION. STEP 1 31 into 8 does not go. So carry the next digit (the 0). STEP 2 31 into 80 goes 2 times but with remainder 18 (Resto 18). STEP 3 Finally carry the 6 and divide again. 31 into 186 goes 6 times exactly (remainder 0). The answer is 26 16 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme UNIT 3. BIG NUMBERS You need to understand the place value of numbers. Each digit in a number has a value which depends on its place in the number. (Decimal System). The 4 represents 4 hundreds 400 units. The 5 represents 5 tens 50 units The 3 represents 3 units 3 units So 453 = 400 + 50 + 3 In a number such as 453 (four hundred and fifty-three) TRY WITH THE NUMBER 859: Learn the name of numbers with more than nine digits: ----- - - billions billones ----Thousand millions Miles de millones/ millardos - - ----- - - ----- ----- ----- ----- millions thousands hundreds tens units millones millares centenas decenas unidades ROUNDED BIG NUMBERS. In real life is not always necessary to use exact numbers. Rounded numbers may be used. Numbers can be rounded to different degrees of accuracy, for example, to the nearest thousand, hundred, ten,.. REMEMBER 1. Look at the digit you are rounding. . 2. Now look at the digit on its right. 3. If it is 4 or less the digit being rounded stays the same. 4. If it is 5 or more the digit you are rounding goes up by 1. 17 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme EXAMPLE: EXERCISES: 1. Round to the nearest ten the following numbers: 23,456 245,205 1,672 2. Round to the nearest hundred the following numbers: 24,012 122,655 1,345,008 3. Round to the nearest thousand the following numbers: 1,506 34,907 12,345,001 4. Round to nearest million the following number: 13,405,543 18 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme UNIT 4. POWERS REMEMBER: In a power, the index tells us how many times the base has to be multiplied by itself. EXAMPLE: 10 2 10 10 (10 squared has two of the same factors) 73 7 7 7 ( 7 cubed has three of the same factors) EXERCISES: 1. Calculate the following: 5 3 = 34 Write down what the base and index is in each case. 2. Calculate the following powers: a) 0 2 ,0 7 ,010 b) 18 ,13 ,12 c) 31 ,51 ,91 d) 2 0 ,50 ,12 0 e) 101 ,10 2 ,10 3 ,10 4 ,105 ,10 6 f) 210 ,35 ,5 4 ,7 3 3. Calculate the squares of the first 15 natural numbers: Number Square 1 2 3 4 5 6 7 8 9 10 11 12 13 14 4. Calculate the cubes of the first 10 natural numbers: Number Cube 1 2 3 4 5 6 7 5. Check: 7 3 35 7 7 7 3 3 3 3 3 343 243 100 6. Calculate: 6 2 14 43 19 8 9 10 15 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme 7. Read and write in words: “5 squared” or 5 2 7 3 “5 to the power of 2” “7 cubed” or “7 to the power of 3” 34 25 If a number is written as a product of factors, then we say it’s written in expanded form, and if it is written in the short form, then we say it’s written in index form. EXAMPLES: Write 11111111 in index form. Solution: 11111111 114 Write 3 6 in expanded form. Solution: 36 3 3 3 3 3 3 EXERCISES: 1. Write in expanded form: 75 10 4 2. Write in index form: 3 3 3 5 55 5 10 10 10 10 10 20 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme GENERAL RULES: 1. Any number to the power of zero is equal to one. 2. Any number to the power of one is equal to the same number. 3. The product of two powers with the same base number is another power with the same base number whose index is the sum of the other two indices. a n a m a nm EXAMPLES: 43 45 (4 4 4) (4 4 4 4 4) 48 435 23 25 2 (2 2 2) (2 2 2 2 2) 2 29 2351 EXERCISES: 1. Calculate the final answer, writing first the answers in index form (use this general rule): 23 27 3 2 33 53 5 2. Write the answer in index form: 7 4 78 7 13 2 133 4 6 4 20 4. The division of two powers with the same base number is another power with the same base number and its index is the difference between the other two indices. a n a m a nm EXAMPLES: 85 83 (8 8 8 8 8) (8 8 8) 82 853 7 6 7 2 (7 7 7 7 7 7) (7 7) 7 4 7 62 21 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme EXERCISE: 3. Calculate the following and write the answers in index form (use this general rule): 27 22 3 7 33 10 8 10 5 5. A product raised to a power is equal to multiply these numbers raised to the same power. (a b) n a n b n EXAMPLE: (2 3) 3 (2 3) (2 3) (2 3) (2 2 2) (3 3 3) 23 33 So, to calculate the result, we can multiply and cube the product, or, we can cube each of the factors and multiply the results. (2 3) 3 63 216 or 23 33 8 27 216 EXERCISE: 3. Calculate the following in the two ways: (2 5) 6 (3 4) 2 6. A division raised to a power is equal to the quotient of both bases raised to the same power. ( a / b) n a n / b n ( a b) n a n b n EXAMPLE: (10 / 5) 3 To calculate the result we have to divide and cube the division: (10 / 5) 3 23 8 Or We can cube each of the factors and divide the results: EXERCISE: 5. Calculate the following in the two ways: (12 / 3) 3 (8 / 4) 4 22 103 / 53 1000 / 125 8 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme 7. A power raised to another power is another power with the same base number raised to the product of these two powers. (a n ) m a nm EXAMPLE: (45 ) 3 45 45 45 4555 415 EXERCISE: 6. Simplify the following, using this general rule: (2 3 ) 6 (5 4 ) 2 NOTES: The same base. The same index. No property. No property. 23 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme UNIT 5. MULTIPLES AND FACTORS. PRIME NUMBERS. LOWEST COMMON MULTIPLE AND HIGHEST COMMON FACTOR. You must know what a multiple and a factor are. A multiple is a number in the times table. You can find them multiplying the number by 1, 2, 3, 4, 5,...... EXAMPLE: The multiples of 4 are: 4,8,12,16,20,24,……. EXERCISE: The multiples of 7 are: A factor is a number that divides into another number exactly. I mean, when the division is an exact division. Remember, in a division: D r d q These terms are called: D= dividend d=divisor q=quotient r=remainder Remember the rule in a division: D d q r When the remainder is 0 (r=0), the division is called exact division. And now EXAMPLE: The factors of 20 are: 1,2,4,5,10,20. (All these numbers divide into 20 exactly). EXERCISE: The factors of 80 are: 24 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme You must know what a prime number is. A prime number is a number with only two factors, itself and 1. A composite number is a number with more than two factors. To find prime numbers, you can use the following tests of divisibility: A number is divisible by: EXERCISE: 2 if the last digit is 0,2,4,6 or 8. 3 if the sum of the digits is a number on the 3 times table. 5 if the last digit is 0 or 5. 11 if the sum of every digit which is in odd place minus the sum of the digits in even place is equal to 0 or 11. Find the prime numbers up to 50 are: FACTORISATION: To factorise a composite number is to write it as a product of prime factors. EXAMPLE: 20 10 5 Divide the number by the first prime numbers 2,3,5,7,11,13,………, and look for factors. 1 EXERCISE: Write as a product of prime factors the number 50 50 25 2 2 5 20 2 2 5 1 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme You must know what the lowest common multiple and the highest common factor are. Abbreviations: ENGLISH SPANISH lowest common multiple LCM mínimo común múltiplo mcm highest common factor máximo común divisor mcd EXAMPLE: STEP 1 STEP 2 STEP 3 HCF Find the HCF of 640 and 192: Write the numbers as the products of their prime factors. Ring the factors in common 84 42 21 7 1 2 2 3 7 360 180 90 45 15 5 1 2 2 2 3 3 5 360 2 2 2 3 3 5 1 84 2 2 3 7 1 360 2 2 2 3 3 5 1 84 2 2 3 7 1 2 2 3 1 12 Multiply all these factors in common The HCF is 12 26 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme EXERCISE: Find the HCF of 250 and 115: STEP 1 STEP 2 STEP 3 The HCF is 5 EXAMPLE: Find the LCM of 640 and 192: STEP 1 Divide and look for the prime factors STEP 2 Write both numbers as a product of their prime factors. STEP 3 Write in index form and ring all the factors with the highest index. 640 320 160 80 40 20 10 5 1 2 2 2 2 2 2 2 5 192 96 48 24 12 6 3 1 640 2 2 2 2 2 2 2 5 1 192 2 2 2 2 2 2 3 1 640 2 7 5 1 192 2 6 3 1 2 7 3 5 1 1920 STEP 4 Multiply all these factors. The answer is 1920 27 2 2 2 2 2 2 3 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme EXERCISE: Find the LCM of 49 and 77: STEP 1 STEP 2 STEP 3 STEP 4 The answer is 539 28 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme UNIT 6. INTEGERS. A) WHAT IS AN INTEGER? DEFINITION: Z ......,4,3,2,1,0,1,2,3,4,5,......... Integers are whole numbers. They can be positive or negative. Positive integers are above zero and negative integers are bellow zero. The integer zero is neutral. It is neither positive nor negative. The sign of an integer is: Positive integers (+) Negative integers (-) Zero (no sign) Two integers are opposites if the distance to 0 is equal, always in opposite directions. One of them will have positive sign and the other negative sign. For instance: 3 and 3 are opposites. Look at the number line: Absolute value: It’s the distance to the 0. You have to take the number without the sign. EXAMPLES: 29 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme B) WHY DO INTEGERS APPEAR? C) ORDERING INTEGERS EXERCISE: Write in order from least to greatest: 1. Place the numbers on the number line. 2. The number which is on the left is the least and the number on the right is the greatest. EXERCISES: 1. Order the following numbers from the least to the greatest: 2. Put in order from the greatest to the least: 3. Write the following integers in order starting from the least: 4. Compare the following whole numbers, circle the greatest and underline the lowest: 30 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme D) ADDING AND SUBTRACTING INTEGERS EXAMPLE: When the number to be added or subtracted is negative, the normal direction of movement is reversed. When two signs are together, these rules are used: () ( ) () ( ) same signs give a positive. different signs EXAMPLES: 2 (3) 2 3 5 3 (5) 3 5 8 5 (2) 5 2 3 6 (4) 6 4 10 31 give a negative. M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme EXERCISES: 1. Adding integers with same sign (you have to add). a) 5 8 13 b) 2 3 5 c) d) e) f) g) h) i) j) k) 6452 3 1 0 5 64 52 4 4 3 2 1 17 5 4 34 573 2 574 1 3 7 4 50 2. Adding two integers with different sign (you have to subtract). a. b. c. d. e. f. g. h. i. j. k. l. m. n. 8 5 50 73 7 20 50 52 48 50 20 27 35 2 1 30 43 502 505 107 110 30 27 32 M. Mar Agüera de Pablo-Blanco IES Caura. Coria del Río Bilingual programme 3. Adding several positives and negatives (you have to collect them). a. 3 4 5 3 2 3 5 3 4 2 11 6 5 b. c. d. e. f. g. h. i. j. 3 4 6 2 1 5 7 5 4 3 2 1 6 4 3 6 5 1 2 7 8 5 3 1 4 8 7 8 0 2 50 15 12 7 3 5 8 7 4 20 7 20 3 1 7 2 50 3 7 5 20 3 1 2 7 5 6 50 20 3 20 1 3 0 4. Work out the answer (eliminate brackets) 3 3 3 3 3 3 3 3 e) j) a) 5 23 7 f) 5 k) 3 b) 3 g) l) 5 2 h) 3 + 2 d) 2 i) 4 c) 5. Work out the answer (remove brackets) 5 3 2 2 3 5 2 2 u) 32 50 m) 4 7 v) 32 50 n) 4 7 o) p) q) r) s) t) w) 5 2 4 7 4 7 2 5 2 5 2 5 50 64 x) 4 7 y) 4 7 z) 4 3 aa) 7 10 bb) 3 8 33 6. Adding and subtracting more than two integers. 3 5 4 3 5 4 5 7 2 a) b) c) d) e) f) g) h) i) j) k) 8 4 5 7 5 4 5 7 5 8 5 4 6 8 7 3 5 3 8 8 8 5 3 3 3 5 22 4 7 2 7 6 3 7 Work out the answer: 10 4 12 30 10 34 12 10 22 10 22 12 a) 12 8 5 9 b) 2 4 13 21 c) 10 4 12 30 d) 15 11 13 43 e) 0 7 4 1 f) 2 2 5 1 g) 24 58 79 48 31 h) 3 11 15 7 2 i) 2 3 4 5 3 j) 7 5 2 7 3 k) 7 5 2 7 3 l) m) 3 15 11 2 7 4 3 5 2 8 34 E) MULTIPLYING AND DIVIDING INTEGERS Multiply and divide the numbers as normal and then find the sign for the answer using these rules: () () ( ) ( ) ( ) ( ) ( ) ( ) two of the same signs give positive. two different signs give negative. The same when dividing EXAMPLES: 3 (5) 15 20 (2) 10 15 (3) 5 40 (8) 5 EXERCISES: 1. Complete the next tables: – 2 +1 – 9 +3 – 6 –5 +7 –1 0 –5 +4 -12 +15 -18 +21 +8 +24 2. Fill in the gaps to make true equalities: a) b) c) d) 5 35 9 0 6 18 4 4 e) f) 7 7 10 0 40 (8) h) (21) (3) g) 35 F) ADDING, SUBTRACTING, MULTIPLYING AND DIVIDING INTEGERS. COMBINED OPERATIONS. 1) Brackets 2) Indices The right order in your operations 3) M ultiplications and Divisions 4) Additions and Subtractions To remember the right order memorize the word BIDMAS EXERCISES: 1. Work out. 5 3 2 5 6 11 a) 3 2 4 b) 2 3 7 c) 2 3 7 d) 7 5 5 e) 7 5 5 f) 3 4 7 g) 5 3 20 h) 5 3 4 i) 5 3 4 5 2 3 2 5 3 4 7 8 23 4 63 8 3 5 3 64 1 25 4 p) 7 3 4 2 j) k) l) m) n) o) q) 2 3 3 6 r) 1 73 5 36 2. Work out. a) b) c) d) 52 7 10 : 2 3 2 50 : 5 1 7 8 : 4 e) 3 2 4 2 f) 5 3 5 3 h) 5 3 7 g) i) j) 2 20 : 10 3 3 7 20 k) 5 3 16 l) 3 5 4 2 3. Work out: 2 3 4 2 7 14 a. 2 5 3 b. 2 5 20 20 25 4 d. 5 7 2 e. 25 30 5 c. f. 3 7 7 4 g. 3 50 55 h. 2 3 5 2 i. 2 3 5 7 j. 1 4 3 2 37 4. Work out. 10 8 : 2 23 4 7 24 35 1 22 3 5 3 23 2 32 42 7 6 7 6 4 8 7 3 8 25 5 4 4 8 3 2 5 52 8 4 24 5. Work out. i. 2 3 4 ii. 2 3 4 iii. 3 5 7 4 iv. 3 5 7 4 v. 3 5 7 4 vi. 3 5 7 4 vii. 2 2 5 7 4 2 2 5 7 4 viii. ix. 2 2 5 7 4 2 2 5 7 4 xi. 2 2 5 7 4 xii. 2 2 5 7 4 x. xiii. 3 3 3 3 xiv. 5 3 2 4 2 5 2 3 38 6. Work out (more than one bracket) a) 3 5 2 8 b) 3 4 2 6 5 7 c) 3 4 2 6 5 7 d) 4 2 3 4 3 5 7 e) 8 5 2 3 4 5 6 4 f) 8 5 2 3 5 5 6 7 g) 16 (9 5 3 12) h) ( 21 11) 13 (4 15 9) i) 5 3 (4 6) 7 ( 8 3) j) (17 5) 3 (5 3 2) k) l) 5 (8 2 3) (4) 6 (2 7) (7) 4 (3 8) 5 (8 5) m) 4 (5 7 3) ( 3) (8 3 4) n) 10 5 (8 3) 5 4 3 2 39 G) TEST ABOUT INTEGERS. 1. Write an integer to represent each situation: a) b) c) d) 10 degrees above zero. A loss of 25 €. In the second basement. 13.2 m of height. 2. Write the four opposite situations. 3. What is the opposite of each integer? -13 +7 -38 +49 0 4. Which is the absolute value of each number in the exercise number 3. 5. Name in English six real life situations in which integers can be used. Spending and earning money Floors in a hotel Temperature 6. How do you read? (4) (5) 1 Positive four minus positive five equals negative one (5) (8) 13 Negative five plus negative eight is equal to negative thirteen (3) (7) 21 Negative three times negative seven equals positive twenty-one (8) (2) 4 Positive eight divided by negative two is negative four (7) (1) (7) (2) (5) (1000) (400) (10) 40 UNIT 7. DECIMAL NUMBERS. A decimal number has a whole number and a fraction. The decimal point in a number separates the whole number from the fraction. The decimal point always comes after the unit digit. Remember the place value of a number: ESPAÑOL ---- ---- ---- ---- , ---- ---- ---- Se llama Millar Centena Decena Unidad Coma decimal Décimas Centésimas Milésimas Abreviatura Valor M 1000 C 100 D 10 U 1 d 0,1 c 0,01 m 0,001 ---- ---- ---- ---- ---- ---- Tenth Hundredth Thousandth t 0.1 h 0.01 th 0.001 ENGLISH ---- , It’s called Thousand Hundred Ten Unit Abbrevation Place value Th 1000 H 100 T 10 U 1 EXAMPLE: 452.945 Decimal point Hundreds Tens Units Tenths Centenas Decenas Unidades Décimas Centésimas Milésimas 400= 4 x 100 50= 5 x 10 2= 2x1 0.9= 9 x 0.1 0.04= 4 x 0.01 0.005= 5 x 0.001 41 Hundredths Thousandths EXERCISES: 1.Look at the worked examples and do the same with the other two numbers: One unit and five hundredths 1.05 2.25 1.05 1 0.05 0.5 3.2 Three units and two tenths 3.2 3 0.2 2.How do you read a decimal number? 452.945 Four hundred and fifty-two point nine four five. Zero point eight. 0.8 3.68 507.913 THE NUMBER LINE We can place decimal numbers on the number line just dividing the units in fractions. 1. First, you have to divide the unit in 10 equal parts, so, you have tenths. 2. Second, if it’s necessary you divide each tenth in another 10 equal parts. Now, you have hundredths. 3. And so on. 42 Observe with attention the figures bellow: |_____|_____|_____|_____|_____|_____|_____|_____|_____|_____| 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Every decimal number can be represented on a number line. Look at the units, then divide the unit in tenths or hundredths. EXAMPLE: 2.35 |______|______|___|___|______|______|______|______|______|______|__ 2 2.1 2.2 2.35 2.3 2.9 COMPARING DECIMAL NUMBERS To compare two or more decimal numbers first compare the units, second the first decimal place value, then the second and so on. EXAMPLE: Place the next numbers in order, starting with the largest: 3.25 0.6 0.56 0.616 0.66 0.62 There is only one with 3 units, the rest of them have no units. So the first is 3.25 Now arrange by comparing the first decimal place. Four of them have the same tenths 0.6 0.616 0.66 0.62 The last one has only 5 tenths 0.56 Now compare the second decimal place (The hundredths): 0.60 0.61 0.66 0.62 So 3.25 > 0.66 > 0.62 > 0.616 > 0.6 > 0.56 (is greater than) EXERCISE: 43 Place in order the next numbers, starting with the smallest: 1.7 1.77 1.78 1.786 1.5 (Use the sign “< , less than”) 7 0.35 ADDING DECIMALS You must know to add decimals. When adding decimals it is important to line up the decimal point. Start from the right. The terms in the addition are called addends and sum or total. Work out the sum 18€ + 4.65€ + 3.99€ =. 44 SUBTRACTING DECIMALS You must know to subtract decimals. When subtracting decimals it is important to line up the decimal point. Don’t forget the minuend has to be greater than the subtrahend. And, start from the right. The terms in the subtraction are called minuend, subtrahend and difference. Work out the difference: 337.495m – 91.65m = MULTIPLYING DECIMALS. You must know to multiply decimals. When multiplying decimals it is important to place the decimal number with more digits above. Multiply the numbers using the same method as you use with natural numbers, I mean, as normal. When you have the product, count how many decimal places the factors have and move the decimal point to the left by this number of places. The terms in the multiplication are called multiplying, multiplier end product. Work out the product: 34.197 ---------------- DIVIDING DECIMALS 45 You must know to divide decimals. When dividing decimals, it is important to know that the divisor has to be an integer. So, if the divisor has no decimal point divide as normal. But, if the divisor has decimal point, you must first to remove it by multiplying by a power of 10. Now, multiply as normal again. 23.7 5 15.2 2.4 250 6.5 985.42 7.3 46 MULTIPLYING AND DIVIDING DECIMALS AND WHOLE NUMBERS BY 10, 100 AND 1000. 1. This is what happens when you multiply decimals and whole numbers by a power of 10 (add 0s or move the decimal point to the right so many times as the exponent indicates). 12.5 10 125 17.68 10 176.8 43 10 430 26.97 100 2697 2.457 100 245.7 3.9 100 390 84 1000 84000 8.456 1000 8456 76.31 1000 76310 2. This what happens when you divide decimals and whole numbers by a power of 10 (remove 0s or move the decimal point to the left so many times as the index indicates). 4500 10 450 369 10 36.9 18.5 10 1.85 7900 100 79 1234 100 12.34 68.7 100 0.687 98760 1000 98.76 6543 1000 6.543 12 1000 0.012 3. Now you try: 123 10 45.7 10 23.89 10 4.478 10 479 100 3.98 100 2345 100 4.98 100 3.4 1000 34.5 1000 47 UNIT 8. FRACTIONS, DECIMALS AND PERCENTAGES. A) WHAT IS A FRACTION? Do you remember decimals? Well, fractions are another way to show numbers that are between the whole numbers. When you divide the whole in equal parts, the fraction appears. A fraction is an indicated quotient between two whole numbers “ ” and “ ”. a has two terms. The top number "a" is called numerator and the b bottom number "b" is called denominator. A fraction B) WHEN FRACTIONS ARE USED? EXAMPLE: Gemma has done an exam with 8 questions. She has got 3 questions wrong. What fraction of the exam did she fail? What fraction of the exam did she pass? ANSWER: 3 8 5 She past 5 of the 8 questions. So, it`s 8 She felt 3 of the 8 questions. So, it´s EXERCISE: Explain the meaning of the following fractions with fraction bars (diagrams): 1 means 1 part out of 6. 6 7 means 7 parts out of 4. 4 means 2 parts out of 5 48 C) READING FRACTIONS. You always read the numerator as a cardinal number and the denominator as an ordinal number. EXAMPLES Two fifths 2 5 8 6 1 10 EXERCISES 4 7 6 9 3 8 Eight sixths One tenth There are three special cases: 1 2 1 3 1 4 One half 2 3 5 2 3 4 One third One quarter It is also possible to read a fraction as: Cardinal number over Cardinal number EXAMPLES 2 11 9 25 EXERCISES Two over eleven 31 76 Nine over twenty-five 7 18 49 D) DIFFERENT TYPES OF FRACTIONS: A fraction like 2 1 3 , , ,.... is called a proper fraction. 5 6 4 A fraction like 6 7 4 , , ,.... is called an improper fraction. 5 2 3 A fraction like 6 8 12 , , ,..... is called a fraction equal to 1. 6 8 12 A proper fraction with its numerator equals one, for example: 1 1 1 1 , , , ,.... is 2 3 4 5 called a unitary fraction. An improper fraction written in this way: 6 5 1 1 is called a mixed fraction. 1 5 5 5 5 Positive fractions are: Negative fractions are: Any fraction like: Any expression like: , ...... , ...... ..... is equal to 0. it’s not a fraction. EXERCISES: 1. Explain the difference between proper and improper fractions: …………………………………………………………………………………………………………………… ……………….......................................................................................................................................................... ................................................................................................................................................................................. . ......................................................................................................................................................................... 2. Explain what a unitary fraction is: .................................................................................................................................................................................. .................................................................................................................................................................................. ............................................................................................................. 3. Write down 2 fractions equals 1 and 2 fractions equals 0: 4. Write like a mixed fraction the following improper fractions: 50 5 3 7 5 11 6 E) FRACTIONS AND DECIMALS. It’s very easy to turn a fraction into a decimal. Just divide the top by the bottom. You can obtain a terminating decimal or a recurring decimal. Convert the following fractions into decimals. EXAMPLES =........ So, 1 0.125 8 (It’s a terminating decimal) ........ So, (It’s a recurring decimal) Convert the following fractions into decimals. EXERCISES Now, turn terminating decimals into fractions. You have to look at where the last digit after the decimal point is. 51 EXAMPLES: 0.3 The last digit is in the tenths column. It’s 3 tenths. 0.12 The last digit is in the hundredths column. It’s 12 hundredths. 2.547 The last digit is in the thousandths column. It’s 2 547 thousandths. EXERCISES: 1. Convert the following terminating decimals into fractions: 1.7 0.85 3.547 2. Investigate with recurring decimals. 52 So, it’s the same as 3 10 So, it’s the same as 12 100 So, it’s the same as 2547 1000 F) A FRACTION LIKE AN OPERATOR. When they’re talking about fractions, people say “of” when they mean “times or multiplied by”. EXAMPLE: What is 1 of 40? 4 ANSWER: 1 of 40 is just 4 1 1 40 40 10 4 4 EXERCISES: Find one-third of each amount: 3, 150, 111 and 96 Find three-quarters of each amount: 120, 300, 8000 and 448 Find three tenths of 60, 210 and 75 53 G) EQUIVALENT FRACTIONS. Equivalent fractions are fractions which have the same value. Fractions can be changed into their equivalent, multiplying or dividing the numerator and denominator by the same number. When you multiply the numerator and denominator by the same number, you are amplifying fractions. When you divide the numerator and denominator by the same number, you are simplifying fractions. EXAMPLES AND EXERCISES: 1 2 2 4 150 15 2250 225 1 2 and are 2 4 equivalent fractions. You have multiplied the numerator and denominator by 2. 1. Find 3 different equivalent fractions amplifying the first one: 150 15 and 2250 225 are equivalent fractions. You have divided the numerator and denominator by 10. 2. Find 2 different equivalent fractions simplifying the first one: EXERCISES: 1.Amplify the following fractions: (Look for 3) (Obtención de fracciones equivalent es por ampliación) 2 7 1 5 7 3 5 6 54 1 2 150 2250 2.Simplify the next fractions (Look for 2) (Obtención de fracciones equivalentes por simplificación.) 12 18 25 125 33 121 100 120 3.Write as simple as possible Look for the irreducible fraction Find the fraction in lowest terms. (Obtención de fracciones irreducibles) 44 154 36 27 13 26 200 2550 H) COMPARING FRACTIONS There are three different ways to order fractions: METHOD 1: Convert fractions into decimals and put them in order. METHOD 2: Use fraction bars and see which has the most shading. METHOD 3: Find equivalent fractions with the same denominator and all you have to do is compare the numerators. 55 EXERCISES: 1.Put 1 2 3 , , in order starting with the biggest. (Use the method1) 3 5 7 2.Put 5 1 2 , , in order starting with the smallest. (Use the method2) 6 2 3 EXAMPLE: 1.Place in order 7 4 3 , and , by converting fractions to a common denominator. (Write 8 5 2 the smallest first). (Para ordenar fracciones has de buscar sus equivalentes con denominador común. Recuerda el denominador común es el m.c.m. de los denominadores) L.C.M (8,5,2) 40 . So the common denominator is 40. 7 35 (5) 8 40 4 32 (8) 5 40 3 60 (20) 2 40 Now, you can order them, using the equivalent fractions: 32 35 60 40 40 40 4 7 3 5 8 2 (less than) EXERCISES: Place in order starting with the greatest(Use the method3) 56 1 1 , 5 6 7 1 , 4 2 2 3 , 5 4 1 2 5 3 , , and 2 7 14 28 I) FRACTIONS, DECIMALS AND PERCENTAGES. A percentage is a part of a whole, expressed in hundredths. EXAMPLES: 3% 25% 50% 3 100 25 100 50 100 57 So, fractions, decimals and percentages are all different ways of expressing parts of a whole. Any fraction can be expressed as a decimal and as a percentage. EXAMPLES: 1 0.5 50% 2 1 0.25 25% 4 3 4 1 3 EXERCISES: 1.Find 10% and 25% of each amount: $100 $300 $50 2.Match these numbers into six sets that show the same number: 0.5 1 1 25% 0.3333.. 5% 0.25 10% 0.1 10 4 50% 0.8 Fraction Decimal number Percentage 4 5 1 1 33% 0.05 3 20 1 80% 2 1 2 0.5 50% 58 J) RATIO AND PROPORTION WHAT IS A RATIO? A ratio is a comparison between two or more quantities. EXAMPLE: A bag of carrots weighs 300g and a bag of potatoes 1.5kg. Calculate the ratio of weight of carrots to weight of potatoes. Both quantities must be in the same units. So: 1.5kg=1 500g So, ratio is 300g : 1 500g Or simplifying ( 300 ) 1 : 5 A ratio can be written as a fraction. So, ratio is 1 5 You can say that the ratio is “ 1 to 5 “ ( 1 es a 5 ) Dividing a quantity in a given ratio. EXAMPLE: 60€ is to be divided between Jon and pat in the ratio 2 : 3. How much money does each one receive? We need to divide 60€ in the ratio 2 : 3. The digits in the ratio represent parts. Jon gets 2 parts. Pat gets 3 parts. And the total is 2+3=5 parts. And the total amount is 60€. So: 5 parts 60€ 1 part 12€ (dividing by 5). So, the final answer is: Jon two parts 2 12 24€ Pat three parts 3 12 36€ Check: 24€+36€=60€ EXERCISE: Three brothers aged 6, 9 and 15 decide to share a tin of toffees in the ratio of their ages (and not in equal parts ). If the tin contains 240 toffees. How many toffees does each brother get? 59 K) OPERATIONS WITH FRACTIONS Addition of fractions. Two or more fractions can be added very easily looking for their equivalents with common denominator. Subtraction of fractions. As for addition, two or more fractions can be subtracted by looking for their equivalents with common denominator. (Be careful with signs) 60 Multiplication of fractions. To multiply fractions all you have to do is multiply together their numerators and their denominators. (Factorise) (Cancel) (Multiply) Division of fractions. To divide two fractions turn the second fraction upside down, change the division sign to a multiplication sign and now is the same as multiplying fractions. (Turn upside down) (Factorise) J) (Cancel) (Operate) TEST1. INTRODUCCIÓN FRACCIONES 1º Escribe la fracción que representa la parte coloreada de cada una de las siguientes figuras: 2º Decir qué fracción de una hora representan: a) b) c) d) e) 15 minutos 30 minutos 45 minutos 10 minutos 20 minutos 3º ¿A cuántos minutos equivalen los 7 de una hora? (Sol: 84 minutos) 5 61 4º Calcula: 2 a) de 60 3 3 b) de 100 4 3 c) de 500 500 d) La mitad de 3 5 12 7 f) La mitad de la quinta parte de 6 e) La tercera parte de 5º Escribe cinco números naturales, cuatro números enteros negativos, tres números fraccionarios positivos y tres números fraccionarios negativos. ¿Son todos racionales? 6º Clasificar los números que figuran a continuación y escribir dos números racionales 4 2 108 equivalentes a cada uno de ellos: 2, , 6, 3 , 8 5 72 7º Escribir cuatro fracciones propias, y otras tantas impropias, cuyo denominador sea 7. 8º Escribe las siguientes fracciones impropias como suma de un número entero y una fracción propia: 19 179 a) c) 25 5 67 1147 b) d) 15 76 62 9º Expresa mediante fracción irreducible, los puntos señalados en los siguientes segmentos de la recta numérica: 10º Transforma en fracciones los siguientes números mixtos: 3 9 a) 2 c) 8 4 10 5 7 b) 7 d) 13 9 11 11º Representa gráficamente los siguientes números racionales: 2 4 13 15 1 16 ; ; 4; ; ; ; ; 3 3 5 2 4 2 3 _________________________________________________________ 12º Escribe cuatro números racionales que sean equivalentes a 6 y tengan por denominador los números: 2, 5, 8 y 15. 13º Escribe una fracción equivalente a 3 cuyo denominador sea 6. 9 14º Añade el término desconocido en las siguientes igualdades: a) 3 Sol: 39 13 169 c) 2 Sol: 8 9 36 b) 16 32 Sol: 18 9 d) 7 Sol: 56 5 40 63 15º Busca la fracción irreducible equivalente a las siguientes fracciones: 144 20 96 21 75 35 105 60 222 243 333 432 540 7200 40500 450 16º Reduce a común denominador las siguientes fracciones: a) 5 4 7 , , 12 9 18 c) 5 8 1 4 , , , 9 21 63 7 b) 8 3 4 , , 25 50 75 d) 11 1 5 7 , , , 45 2 18 30 17º Ordena de menor a mayor las siguientes fracciones: a) 1 3 1 3 5 , , , , 2 4 3 2 6 b) 2, 1 19 7 , , 1, 0, 9 9 9 18º Escribe dos números racionales, comprendidos entre: 2 3 y a) 3 4 b) 1 1 y 5 7 c) 7 8 y 5 5 64 19º Jorge ha comido los dos quintos de una tortilla mientras que su hermana Susana ha comido los tres séptimos. ¿Quién ha comido más? Sol: Susana 9 5 de la edad de su padre, en tanto que su hermano Luis es los . 20 12 ¿Quién es mayor? Sol: José 20º La edad de José es los L)TEST2. OPERACIONES CON FRACCIONES 1º Efectúa las siguientes sumas de fracciones, simplificando los resultados: a) b) c) d) e) f) g) h) i) j) k) l) 9 5 13 13 5 9 8 16 7 5 1 12 12 12 2 7 6 11 11 11 7 5 3 12 6 4 7 3 3 2 8 4 10 5 1 3 7 11 8 4 12 24 5 3 3 7 8 20 4 5 1 1 1 1 2 1 2 2 3 2 3 5 1 2 3 6 3 2 7 2 5 3 2 1 5 2 3 65 2º Efectúa las siguientes multiplicaciones, simplificando los resultados: a) 8 5 15 12 b) 4 2 5 3 5 6 c) 4 7 7 3 d) 6 14 5 4 7 23 6 e) 1 3 4 2 7 f) 3 7 11 13 4 9 13 7 3º Efectúa las siguientes divisiones, simplificando los resultados: a) 2 :4 7 b) 3 : 9 4 c) 4 10 : 9 3 d) 11 6 : 4 7 9 16 e) 6 : f) 5 5 : 4 8 66 Bilingual Programme. M. Mar Agüera de Pablo-Blanco. IES Caura. Coria del Río. M) 2 3 TEST3. POTENCIAS DE FRACCIONES. 3 g) 1 4 2 h) i) 2 5 0 2 3 j) 4 k) 2 4 2 4 l) 5 m) 2 3 5 3 3 1 o) 3 2 n) 5 5 2 3 1 1 p) 2 5 2 2 q) 3 3 1 2 r) 2 3 Remember: = 67 Bilingual Programme. M. Mar Agüera de Pablo-Blanco. IES Caura. Coria del Río. M) TEST4. ABOUT FRACTIONS 1.Translate into English: Fracciones irreducibles. Multiplicar las fracciones del primer ejercicio. Fracciones propias e impropias. Ordena las siguientes fracciones de menor a mayor. Simplifica la fracción. Para sumar y restar fracciones, busca su denominador común. 2.Exercises: 48 120 Simplify: Write from greatest to least: 1 2 7 , , 2 5 3 Convert the fraction 10 into a 30 decimal. Convert the percentage 80% into a fraction. 68 Bilingual Programme. M. Mar Agüera de Pablo-Blanco. IES Caura. Coria del Río. Write the next improper fractions as mixed numbers: 4 11 , . 3 2 Work out: 1 3 2 4 Work out: 1 1 6 2 3 5 Work out: 1 4 5 2 25 7 Find 3 of 65 Kg. 5 Find 30% of 45 € 3.How do you read? 3 7 43 4 5 20 1 3 3 2 5 10 69