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Name 7th Grade Summer Math Packet For Students who will be enrolled in Mrs. Kohrman's 7th Grade Math Class in the 2015/2016 school year. AN.M.Y.Or DATE CLASS NAME 1-1 The Order of the Four Basic Operations UNIT I- OBJECTIVE: Finding the value of an expression that involves whole number addition, subtraction, multiplication, or division 41\ co The four basic operations of mathematics are addition, subtraction, multiplication, and division. Finding the value of some expressions involves two or more of these operations. The order in which you perform the operations is very important. 4;(4 )?e. ,3\ The Order of the Four Basic Operations First multiply and divide in order from left to right. Then add and subtract in order from left to right. Find the value of each expression. a. 16 + 8 X 5 EXAMPLE b. 24 — 6 ± 2 + 1 II Solution Copyright ® by Holt. Rinehart and Winston. All rights reserved. a. 16 + 8 X 5 16 + 40 56 First multiply. Then add. b. 24— 6 + 2 + 1 24 — 3 + 1 21 + 1 22 First divide. Then subtract. Then add. Find the value of each expression. 1. 20 — 9 + 7 2. 16 + 30 —22 3. 25 —6 + 14— 4 4. 15 + 5 — 14 + 6 5. 18 + 3 X 2 6. 15 X 10 + 5 7. 12 X 6 + 3 X 4 8. 16 + 8 X 4 + 2 9. 27 — 12 + 3 10. 14 + 9 X 2 11. 48 + 6 — 2 X 2 12. 9 X 8 — 6 + 3 13. 21 + 12 + 3 + 1 14. 32 — 2 X 4 + 12 15. 36 — 16 + 4 X 4 16. 40 + 2 X 4 — 2 17. 72 + 3 + 6 X 3 — 2 18. 4 X 10 + 5 — 1 + 3 Making Sense of Numbers Unit 1 Order of Operations and Number Theory 1 DATE CLASS NAME UNIT_ P1reLJ es aud the 0:aler of Orations 1 JECTIVE: Finding the value of an expression that contains parentheses Often an expression contains parentheses. To find its value, you first perform any operations inside the parentheses. Remember to follow the correct order of the four basic operations. EXAM LE 1 Find the value of (9 + 3) X (17 — 8). Solution (9 + 3) X (17 — 8) 12 X 9 108 First work inside the parentheses. Then multiply. Find the value of 92 — 6(5 + 8). Solution 92 — 6(5 + 8) 92 — 6(13) 92 — 78 14 First work inside the parentheses. Then multiply. Note that 6(13) means X 15. Then subtract. Find the value of each expression. 2. (35 — 6) X 4 3. (12 — 4) + 2 4. (22 + 19) X 10 5. 36 X (12 + 6) 6. 45 — (9 + 27) 7. (18 — 3) X (4 + 7) 8. (25 — 9) + (3 + 5) 9. 38 — (14 — 2) + 9 10. 9 X (24 — 16) + 4 H. 27 + (3 + 14) X 6 12. 60 — (4 X 8) + 2 13. 6(33 — 29) 14. (41 + 39)2 15. 47 + 2(12 — 9) 16. 90 — 3(8 + 5) 17. 74 + (17 — 6) X (6 + 2) 18. (49 — 7) + (7 — 4) X 2 19. (16 — 2 X 4) + (64 + 4 + 2) 20. 36 + (9 X 2) + (6 +18 Unit 1 Order of Operations and Number Theory Rinehartand Winston. All rightsreserved. Copyright © by Holt, 1. 54 + (2 + 4) 2) Making Sense of Numbers NAME CLASS DATE Us! ig Formulas UNIT I OBJECTIVE: Finding an unknown quantity by applying a formula A formula is a mathematical sentence that describes how two or more quantities are related. If you know the value of all quantities except one, you can use the formula to find the unknown quantity. The following are some basic formulas from geometry. Some Basic Geometric Formulas Rectangle with length .e and width w perimeter: P = 2x,e+ 2 X w area: A = _e X w Square with one side of length s perimeter: P = 4 X s Cube with one edge of length e surface area: S ---- 6 X e2 EXAMPLE area: A = s2 ./e volume: V =- e3 The length of a rectangle is 19 and its width is 13. Find the perimeter of this rectangle. SoiLllon Write the rectrigle perimeter formula. P = 2 X 19 + 2 X 13 + 26 Replace with 19. Replace w with 13. Multiply first. 64 Then add, P= P= 38 Copyright© by Holt, Rinehartand Winston. Allrightsreserved. P=2X _e +2X w Find each quantity using one of the formulas given above. 1, the area of a rectangle with length 39 and width 9 2. the perimeter of a square with one side of length 58 3. the perimeter of a rectangle with length 12 and width 7 4. the perimeter of a rectangle with length 38 and width 23 5. the area of a square with one side of length 16 6. the surface area of a cube with one edge of length 12 7. the volume of a cube with one edge of length 10 8. the volume of a cube with one edge of length 21 6 Unit 1 Order of Operations and Number Theory Making Sense of Numbers NAME DATE CLASS ivalent Fractions: Higher Terms UNIT 2 OBJECTIVE: Writing an equivalent fraction with a greater denominator by drawing a model or by multiplying Fractions that represent the same amount are called equivalent fractions. If a fraction is renamed with a denominator that is greater than the given denominator, it is written in higher terms. Rewrite the statement at right. Replace ? with the number that makes the fractions equivalent. Solution Method 1 Draw a model 2 of two thirds. 3 Split each third 8 into four parts 12 to make twelfths. 2 Using either method, you can write — = 3 12 2_? 3 12 Method 2 Multiply both the numerator and denominator by 4. 2 2X4 8 3 3 X 4 12 Method 2 above uses the following rule for equivalent fractions. Equivalent Fractions: Higher Terms number. Rewrite each statement. Replace ? with the number that makes the fractions equivalent. ? 1 1. — = 4 12 2. 1_? 5 10 3. 3 ? 4 16 5. 7_? 312 9 ? 6. 3 = 7 _ ? 7 14 8. 9 ? 8 56 11. 13 _ ? 9 —54 6 ? 13. — = 7 91 14. 11 _ ? 8 96 22 3 Unit 2 Fractions 2 ? 3 6 Making Sense of Numbers Copyright0 by Holt, Rinehartand Wi nston. All rightsreserved. To write a given fraction as an equivalent fraction in higher terms, multiply both the numerator and denominator by the same nonzero DATE CLASS NAME 3-7 UNIT 2 Equivalent Fractions: Lower Terms OBJECTIVE: Writing an equivalent fraction with a lesser denominator by drawing a model or by dividing Fractions that represent the same amount are called equivalent fractions. If a fraction is renamed with a denominator that is less than the given denominator, it is written in lower terms. Rewrite the statement at right. Replace ? with the number that makes the fractions equivalent. 6_? -3 Solution Method 1 Draw a model 6 of six-tenths. 10 Redraw each 3 two-tenths 5 as one-fifth. 3 Using either method, you can write = 10 5' Method 2 Divide both the numerator and denominator by 2. 6_6÷2 _3 10 - 10 ± 2 - 5 Method 2 above uses the following rule for equivalent fractions. Copyright © by Holt, R inehart andWinston. All rights reserved. Equivalent Fractions: Lower Terms To write a given fraction as an equivalent fraction in lower terms, divide both the numerator and denominator by,the same nonzero number. Rewrite each statement. Replace ? with the number that makes the fractions equivalent. 1• 6 8 _ ? 2. 4 ? 4 4. 1-0- = 3 36 10. 20 5. ? = 54 ? = 364 36 ? 13. 7-4g = -4 Making Sense of Numbers 4 12 _ ? 3 ? =4 81_? 8. 11. 32 = 3 ? 1l0 ? 14. -3-5- _ 9 ? 3*12 = 4 6. 30 ? T = 16 _ ? 9. 12. 24 ? = 5- 175 15' ? = Unit 2 Fractions 23 NAME DATE CLASS 3-8 UNIT 2 Lowest Terms of a Fraction OBJECTIVE: Writing a fraction in lowest terms A fraction is in lowest terms if its numerator and denominator have no common factor other than 1. Write —in lowest terms. Solution Method 1 Divide both the numerator and denominator by common factors until their greatest common factor (GCF) is 1. 54 54 ÷ 2 — 27 > 27 — 27 + 3 — 9 Method 2 Divide both the numerator and denominator by their GCF. The GCF of 48 and 54 ie 6. You can also use prime factors to write a fraction in lowest terms. EXAMPLE 2 • 96 , Write — in lowest terms. 84 Solution 96 25 X 31 84 — 22 x 3ix 71 ><><2X2X20 8 —— V/X IX 7 7 Write each fraction in lowest terms. 4 1. -a 9 2. 13 . 15 5. rid 35 6. -;(7) 7. 36 9. T3. 42 10.18 68 13. il 17. 24 189 126 Unit 2 Fractions 6 48 4. 4 28 12 18 18 8. ... •45 4D 14 11. T2- 18 12. n 14. 65 78 15. 34 51 95 16. T8- 18. 132 198 19. 273 195 20. 171 513 Making Sense of Numbers Copyright © by Holt, Rinehartand Winston. AUrightsreserved. Write the prime factorization of the numerator and the denominator. Divide by all common prime factors. DATE CLASS NAME • 4-2 Adding Fractions: Like Denominators UNIT 2 OBJECTIVE: Finding sums of two or more fractions with like denominators To add fractions that have like denominators, you can use the following method. Adding Fractions with Like Denominators 1. Add the numerators. 2. Write the sum from Step 1 over the like denominator. 3. If necessary, rewrite the result from Step 2 in lowest terms. EXAMPLE 1 5 1 b. + 5 1 Write each sum in lowest terms. a. + Solution 5 1 5+1 -77 - - 76 5 1 b. 12+ 12 = 5+1_6 1 E 2 Sometimes a sum of fractions is a whole number or a mixed number. 2 7 Write each sum in lowest terms. a. -§ + 4 7 3 b. + Solution Copyright 0by Holt. Rinehart andWinston. All rights reserved. 2 7 2+7_ 2 9—9 11 7 3 7+3 10 8 = b -8 + 8- =5= 1 14 Write each sum in lowest terms. 2 1. 3 + 32 3 1 4. m + 10 7 7 4 7 7 2 1 10. a + 13. -§- + 1 4 + 5. 15 8 15 2 15 13 1 11 1 3. a + 7 9. + 5 14. 13 5 5 + 5 11 12. 12 + 12 11. 1-2- + 7 1 2- 4 13 8 73 + 71 + 75 9 5 10 11 5 17 • 7 1 17. §. + § + 4 Making Sense of Numbers Unit 2 Fractions 33 NAME DATE CLASS rs Ad, ling Fractions: Unlike D (11,,L UNIT 2 OBJECTIVE: Finding sums of two or more fractions with unlike denominators To add fractions that have unlike denominators, you must first write equivalent fractions that have a common denominator. Then add using the method for fractions with like denominators. k 3 5 3 1 Write each sum in lowest terms. a° 8 u° 4 2 S lution a. The LCM of 8 and 2 is 8. So the least common denominator is 8. 1 First Then add. rewrite 2. 3 1 3 4 3+4 7 1 1 X4 4 + = + 8 8 2 2X48 8 2 8 8 b. The LCM of 4 and 6 is 12. So the least common denominator is 12. 3 5 Then add. First rewrite - and 4 6 3 5 9 10 9 + 10 19 3 3X3 9 + = + = 12 12 4 6 12 12 4 4 X 3 12 5 6 5X2 6X2 7 = 1— 12 10 12 Write each sum in lowest terms. 4 R 7 1 1 1 1 17 3 1 6 8 11. 3 1 7 13. g + 4 + -8- 5 11 12. m 1 + RI 5 7 + ii 273 1 3 3 14. - + - + 5 5 4 5 2 7 16. - + — + 3 12 6 1 1 1 18. - + - + — 6 4 14 8 3 5 20. - + — + — 9 1 5 10 34 Unit 2 Fractions Making Sense of Numbers rightsreserved. Copyright CD by Holt, Rineha rtand Winston. All 1 8 1. -3- + 3-- DATE CLASS NAME 4-4 Adding Mixed Numbers: Like Denominators UNIT 2 OBJECTIVE: Finding sums of mixed numbers with like denominators To add mixed numbers that have like denominators, you can use the following method. Adding Mixed Numbers with Like Denominators 1. Add the fractions. 2. Add the whole numbers. 3. If necessary, rename the whole number in the sum. 4. If necessary, rewrite the sum in lowest terms. Write each sum in lowest terms. 8 6 5 1 7 b. 27 + 1 c. 3-4 + a. 4-i-5 + 2I0-- EXAMPLE 01. Solution 1 a. 4T6 7 Copyright 0by Holt, Rinehart andW inston. All rights reserv 8 6-17 1) b. 6 27 +1 6 3- c. 32 9 8 + 2- 13 Rename the whole number. 4 4 Write each sum in lowest terms. 3 1 1. 93 + 63 2 2 2. 7- + 19 9 5 1 3. 2- + 38 8 1 1 4. 46 6 + 5- 3 5. 1-m- + 5 3 6. 8 + 48 5 1 7. 37 + 7 7 1 8. 1-2- + 5E 13 7 2 ) + To10. 4 7 8 1 11. 59 + 79 4 7 13. 19 9 + 5- 11 8 14. 2 3 + 4 3 1 3 2 12. 13 + 6. 1 3 1 16. 78 + 18 + 98 5 5 15. 9- + 86 6 4 1 4 17. 39 + 109 + 29 6 2 4 18. 8- + 3- + 37 7 7 7 1 7 19. 19 + 39 + 69 Making Sense of Numbers Unit 2 Fractions 35 NAME DATE CLASS A 'ding Met! UNIT 2 OBJECTIVE: Finding sums of mixed numbers with unlike denominators To add mixed numbers that have unlike denominators, you must first write equivalent mixed numbers that have a common denominator. Then add using the method for mixed numbers with like denominators. 7 -1 1 7 b. 4- + 3 6 + 3Write each sum in lowest terms. a. 810 8 5 SCutiou b. The LCM of 8 and 6 is 24. a. The LCM of 5 and 10 is 10. So the least common So the least common denominator is 24. denominator is 10. 7 21 1 2 488 i-o424 8 5 1 4 7 7 + 3 10 +3— + 3- -4 +3 10 6 9 1110 25 1 1 7= 7 + 1= 824 24 24 Write each sum in lowest terms. 1 3 2. 9- + 32 8 1 5 + 23. 53 12 3 1 4. 8- + 214 2 3 1 + 25. 14 10 1 4 6. 36 + 115 1 7 7. 2- + 84 17 ". 18 ' 1 9 1 5 9. 7- + 2 6 Q 11 7 2 10. E +5- 13. 4 -8 + 19 6 7 5 16. 3- + 18 10 1 6 +11. 32 7 2 4 12. 3 + 13 4 7 1h 14. § + 6 T 3 5 15. 5- + 86 4 19 1 — + 4 12 17. 4 20 11 11 18. 7-17 5 + 212 1 1 1 19. 1- + 6- + 84 4 8 2 1 2 20. 2- + 4- + 93 6 3 4 2 1 +21. 1- + 35 2 5 7 3 1 22. 94 + 68 + 24 7 1 3 23. 4- + 2- + 95 10 2 3 5 11 24. 8- + - + 24 6 12 36 Unit 2 Fractions Making Sense of Numbers Copyright © by Holt, Rinehartand Winston . All righ 2 1 1. 63 + 76 1 DATE CLASS NAME 5-2 UNIT 2 Subtracting Fractions: Like Denominators OBJECTIVE: Finding differences of two fractions with like denominators To subtract fractions that have like denominators, you can use a method similar to that for adding fractions with like denominators. Subtracting Fractions with Like Denominators 1.Subtract the numerators. 2. Write the difference from Step 1 over the like denominator. 3. If necessary, rewrite the result from Step 2 in lowest terms. EXAMPLE 1 EXAMPLE 2 2 8 Write each difference in lowest terms.11a — 11 Solution 9 2_8—2_6 8 b * isT) M= a' — — 11 Find the difference 1 — 30 b. — T- 15 5 4 Copyright 0by Holt. Rinehart andWinston. All rights reserved Solution 15-2 . 13 2 15 2 15. 1 — ID = 15 51 . 15 Th5Rewrite 1 as Write each difference in lowest terms. 5 1 11 1 4 12 2. --i — i.- . 3 1 3' i — i 5 173 18 — M 8 5 9 9 7 1 8 — -i 11 5 11. 1 — TA 13 12. 1 — To- 5 1 • 1 10. 1 — yo- Find the value of each expression by using the order of operations. 8 15. 9 18. 1 — (1 — Making Sense of Numbers Unit 2 Fractions 41 NAME DATE CLASS 53 Subtracting Fractions: Unlike Denominators UNIT 2 OBJECTIVE: Finding differences of two fractions with unlike denominators To subtract fractions that have unlike denominators, you must first write equivalent fractions that have a common denominator. Then subtract using the method for like denominators. 5 3 b. — 1—4 23 2 30 5 Write each difference in lowest terms. Solution a. The LCM of 30 and 5 is 30. So the least common denominator is 30. 2 First rewrite-6. 2 5 2X6 5X6 Then subtract. 12 30 23 30 23 30 2 5 12 30 23 — 12 30 9 42 35 — 9 42 11 30 b. The LCM of 6 and 14 is 42. So the least common denominator is 42. 3 14 35 42 26 42 _13 21 Write each difference in lowest terms. 5 1•8 • 11 2 — 12 3 1 2 a 31 3 — 36 4 7 1 1 1 4 6. — § 1 1 O 4 6 10 '" 5 7 9 1 10.14 — 12. To — Find the value of each expression by using the order of operations. 11 (7 1\ \ 8 2/ 16. 42 1 8 /17 2\ _ 1 18 3/ 6 Unit 2 Fractions 11 /1 —1) 15. — — — — 12 3 6 18. /9 _ 1\ _ 1 00 2/ 3 Making Sense of Numbers Aq 1q6uAdoo 5 6 IAA p ue 5 5 X 7 35 6 6 X 7 42 9 3 3X3 14 14 X 3 42 Then subtract. amuse.' sppp IIV 5 3 First rewrite — arid — 14: DATE CLASS NAME 5-4 UNIT 2 Subtracting Mixed Numbers Without Renaming OBJECTIVE: Finding differences of mixed numbers without renaming the whole-number part To subtract mixed numbers, you use the following general method. Subtracting Mixed Numbers without Renaming 1. If necessary, write equivalent mixed numbers that have a common denominator. 2. Subtract the fractions. 3. Subtract the whole numbers. 4. If necessary, rewrite the difference in lowest terms. Copyright 0by Holt. Rinehart and Winston. A ll rights reserved. EXAMPLE 7 1 — 3Write each difference hi lowest terms. a. 58 8 Solution 3 7 b. 51- —> a. 58 1 1 — 1— 33 8 6 3 Rewrite the = 2 .71 difference in 3 1 b. 53 4 — 19 5E 4 Write equivalent mixed numbers with common denominators. 5 lowest terms. Write each difference in lowest terms. 11 4 1. 6-it — 513 7 2 2. 129 —4 3. 7.2ii — 3u 6 1 4. 97 — 7 7 5. 5- — 2 8 1 6. 142 — 10 1 4 7. 85 — 85 14 7 8. 1.17 — 1 1 9 9. 6 — 10 — 310 8 2 10. 15-§ — 4§ 5 3 11. 1 -8- — 11 1 12. 18E — E 7 2 13. 57) — 33 7 2 — 214.113 12 1 1 15. 5- — 16 18 19 3 16. 7yo — 64 13 2 17. 10-rg — 1 1 18. 93 — E Making Sense of Numbers Unit 2 Fractions 43 NAME CLASS DATE Multiplying Two Fractions 'II, 33 3 7 2 . OBJECTIVE: Finding the product of two fractions To multiply two fractions, you can use the following method. Multiplying Fractions 1. Multiply the numerators. 2. Multiply the denominators. 3. If possible, divide both numerator and denominator by a common factor. This will give you the final product in lowest terms. EXAMPLE Write each product in lowest terms. a. 4 b . 11 3 5 c. § Soluton a. 1 5 1X5 5 4 6 4 X 6 24 1X3 1l 1 _-11 ight 0 by Holt, Rinehart and Winston. All rights reserved. 5 X 2 10 3 X 7 21 Divide each 4 by 4. Divide 6 at 9 Write each product in lowest terms. 1. 1 X 1 2 4 2 4. ,7 1 7. g 5. § 3 4 8. —. 1 1 4 11. 1/ 2 3 13. -;-, X 9 8 5 14. i-g 4 16. 25 36 5 17. 4 21 i5 32 27 20 19. 77. 52, 21 20. 7: Making Sense of Numbers 8 — 2 25 16 Unit 2 Fractions 53 NAME UNIT DATE CLASS Multiplying With Mixed Numbers 2 OBJECTIVE: Finding products that involve mixed numbers To multiply with mixed numbers, use the following method. Multiplying With Mixed Numbers 1. Write each mixed number and whole number as a fraction. 2. Multiply the fractions. 3. If necessary, rewrite the result from Step 2 in lowest terms. Write each product in lowest terms. a. Sohitiorii 1 1 1 33 a. X4 = 7.J 8 l 1 1 1 b. 3- X 52 3 1 1 b. 3- X 5 3 2 1 X 48 7 — 2 16 11 X 8 1 X 11 1X8 _ 11 _ 13 8 8 3 1 4. X 3i 2 1 7. - X 4- 3 2 8. 2- 3 9. 12 X 23 4 1 11. 14 X 24 12. 2- X 16 5 6 3 4 2 1 15. 1- X 23 4 1 3 14. 1- X 2- 1 6 1 16. 3- X — X 92 7 3 17. 4- X 2 1 18. 7- X 8 X 22 5 7 3 19. 1- X 3- X 6 9 4 56 Unit 2 Fractions 4 1 5 — Making Sense of Numbers CopyrightCD by Holt, Rinehartand Wi nston . Allri ghtsreserved . Write each product in lowest terms. CLASS NAME DATE 7-2 Reciprocals UNIT 2 OBJECTIVE: Finding the reciprocal of a given number Two numbers whose product is 1 are called reciprocals of each other. The following are some examples of reciprocals. 1 2 3x7 7 3 =1 8x 17.7 =1 1 5X3=1 Every number except zero has exactly one reciprocal. Zero has no reciprocal. To find the reciprocal of a number, write it in fraction form and interchange the numerator and denominator. rniErATINIm Write the reciprocal of each number. a. 10 Solution 2 11 a. 11 2 The reciprocal 211 of ITs in T. Copyright © by Holt, Rinehart andW inston. AD rights reserved. • 0 b. 8 = IX 2 c. 3i The reciprocal .1 .1 of 8 is 8' b. 8 c. 3 2 =VX1*7 The reciprocal . 5 of 33 is . Write the reciprocal of each number as a whole number or as a fraction in lowest terms. If there is no reciprocal, write none. 5 1. -§ 14 2. i 1 1 5. 6.200 1 10. 3.-1 9. 1-.1- 3.12 4. 50 7.0 8.1 5 11. 46 11 12. 8E Tell whether the numbers in each pair are reciprocals of each other. Write Yes or No. 1 13. 16, -1E6- 14. 1 10 16. 1 , 10 . 6 7 15. 14 4' 5 18. 0, 1 'T Fill in each blank with the number that makes the statement true. 1 19. 7 X 17 = T. 1 20. i X 22. x8 3= 1 25. 2 X 7=1 3 Making Sense of Numbers =1 3 7 23. 5X -= 7 38 26. 1 X =1 21. 23 X =1 3 X 24. -0 =1 27. 13 X Unit 2 Fractions 67 NAME DATE CLASS Divid. ig With Fractions UNIT OBJECTIVE: Finding quotients involving fractions 2 62 6 In the division — ± — — is the dividend — is the divisor, and the result of 3 7' 3 '7 this division is called a quotient. To divide by a fraction, you can use the following rule. Dividing by a Fraction 1. Multiply the dividend by the reciprocal of the divisor. 2. If necessary, rewrite the result from Step 1 in lowest terms. EXAMPLE 1 2 Write the quotient -3- ± ,7 6 in lowest terms. Solution 1 7_ ZX71X77 6 3X 3X39 2.6 3*7 When a division involves a whole number, write the whole number as a fraction with denominator 1. n EXAMPLE 2 1 Write each quotient in lowest terms. a. 3 ± 3 Solution 1. 3 1. y= 8 6 8 b. 6 ± — = ± — = 9 9 1_ 1 A 1 1X1 1 9 _ 3 X 9 _ 27 1 X 4 4 63 4 Write each quotient in lowest terms. 1. 68 2.3 7 5 3.2 2. —5 2.2 9•3 6. Unit 2 Fractions 2.2 3. 4 ± 2 1 1 7. 5 . 3 24 10. — ± 25 5 4 . 8 11. § 15 14. - 1 . - 6 3 15. — ± 2 5 2 . 18. -0- 4 19. 6 ± — 2 4. 2.4 8. 1.1 -,- -7- 1 Making Sense of Numbers Copyright © by Holt, Rinehartand Winston. All ri a. CLASS NAME $ UNir 3 DATE Riu 'TA lecim s OBJECTIVE: Rounding decimals When you round a decimal, you replace the given decimal with a number that terminates at the specified decimal place. ounal each decimal to the specified decimal place. a. 24.567 to the nearest hundredth b. 18.42 to the nearest tenth c. 93.5 to the nearest whole number Solution a. Identify the digit in the hundredths place. Look at the digit to its right. This is the hundredths place. Since the digit in the thousandths place is more than 5, replace S with 7. Thus, 24.567 rounded to the nearest hundredth is 24.57. 24.56©-0 b. Identify the digit in the tenths place. Look at the digit to its right. This is the tenths place. Since the digit in the hundredths place is less than 5, leave 4 as 4. Thus, 18.42 rounded to the nearest tenth is 18.4. Copyright ©by Ho lt, Rinehart an d Winston. All rights reserv 18.4© c. Identify the digit in the units place. Look at the digit to its right. This is the units place. Since the digit in the tenths place is 5, replace 5 with 4. Thus, 93.5 rounded to the nearest whole number is 94. 93.0 1 Round each decimal to the specified decimal place. L 123.451; nearest hundredth 2. 123.45; nearest tenth 3. 0.333; nearest tenth 4. 0.543; nearest hundredth 5. 19.95; nearest whole number 6. 8.09; nearest whole number 7. 3.141; nearest hundredth 8. 1.414; nearest tenth 9. 0.0045; nearest thousandth 11. 18.001; nearest whole number Making Sense of Numbers 10. 0.056; nearest tenth 12. 3.89; nearest whole number Unit 3 Decimals 85 DATE CLASS NAME DecimE s UNIT 3 OBJECTIVE: Adding decimals You add decimals by using what you know about decimals together with what you know about adding whole numbers. Recall that all whole numbers are decimals with an invisible decimal point. 23 = 23.0 Recall that you can place O's at the far right of a decimal and get an equivalent decimal. 15.7 = 15.700 15.7 = 15.70 .60321669111•1 Adding Decimals 1. Arrange the decimals so that decimal points align. Add zeros as needed to make equivalent decimals Then place the decimal point in the sum. 2. Add as with whole numbers. Add: 23 + 15.75 + 14.6 Solution 2. Add as with whole numbers. 1. Arrange the decimals. 23. 00 Acid two zeros. 15. 75 + 14. 60 1213 Add one zero. Place the decimal point the sum. . 00 15. 75 + 14. 60 53. 35 Therefore, 23 + 15.75 + 14.6 = 53.35. Add. 1. 11.4 + 20.3 2. 7.5 + 8.5 3. 21.6 + 21 8 4. 11 + 54.8 5. 19.5 + 24.84 6. 9.3 + 12.78 7. 42 + 34.95 + 18.5 8. 18.1 + 13.2 + 19.65 9. 13.4 + 28 + 19.5 10. 94.95 + 89.9 + 17.49 11. 7.8 + 17 + 11.98 + 27.79 12. 28.19 + 12 + 45.15 + 17.40 13. 10 + 18 + 37.3 + 43.1 14. 100.45 + 32 + 18.9 + 18 3 Making Sense of Numbers Unit 3 Decimals 91 NAME CLASS 9 5 DATE S uL racting Decim s UNIT 3 OBJECTIVE: Finding the difference when one decimal is subtracted from another You subtract one decimal from another by using what you know about decimals together with what you know about subtracting whole numbers. Subtracting Decimals 1. Arrange the decimals so that decimal points align. Then place the decimal point in the difference. Add zeros as needed to make equivalent decimals. 2. Subtract as with whole numbers. EXAMPLE 1 • .. Subtract: 10 - 4.04 Solution Subtract as with whole numbers. Align decimal points. 10. 00 Acid -two zeros. 10. 00 - 4. 04 - 4. 04 Place the decimal 5. 96 point in the difference. Copyright © by Holt, Rinehart andWinston. All rights reserved. Therefore, 10 - 4.04 = 5.96. EXAMPLE 2 Subtract: 98.24 - 74.39 Solution Align decimal points. Subtract as with whole numbers. 9 8. 2 4 98. 24 - 74. 39 -74.39 Place the decimal 2 3. 8 5 point in the difference. Therefore, 98.24 - 74.39 = 23.85. Subtract. 1. 12 - 8.7 2. 20 - 19.9 3. 100 - 99.95 4. 18 - 0.1 5. 14.22 - 12.66 6. 8.38 - 43 7. 18.1 - 16.41 8. 13.88 - 12.5 9. 10.89 - 9.89 10. 11.3 - 11.28 11. 96.3 - 96.03 Making Sense of Numbers 12. 16.7 - 126 Unit 3 Decimals 95 CLASS NAME 9 UNIT $ DATE Adding and Subtracting with Decimals OBJECTIVE: Finding the value of an expression involving both addition and subtraction of decimals To find the value of an expression involving both addition and subtraction, follow the order of operations. EXAMPLE 1 Evaluate 43.24 + 18.11 - 50.89. Solution 43.24 + 18.11 - 50.89 = 61.35 - 50.89 = 10.46 Thus, 43.24 + 18.11 -50.89 = 10.46. EXAMPLE 2 Add 43.24 arid 13.11. Subtract 50.59 from 01.35. Evaluate 132.5 - (45.98 + 23.76). Solution 132.5 - (45.98 + 23.76) = 132.5 - 69.74 = 62.76 Thus, 132.5 - (45.98 + 23.76) = 62.76. Add 45.95 and 23,70. Subtract 09.74 from 132.5. Copyright 0by Holt, Rinehart andW inston. Al l rights reserved. Evaluate each expression. 1. 16.2 + 18.1 - 7.1 2. 100 - (33.22 + 55.1) 3. 13.2 - (0.5 + 9.4) 4. 1200 - (1000 + 45.8) 5. 18.45 - 10.88 + 18 6. 127.41 - 100 + 17.99 7. 1.45 - 1.08 - 0.18 8. 0.45 - 0.11 - 0.18 9. 70.16 - (60.5 - 50.9) 10. 112 - (80.1 - 79.3) 11. 92.17 + 19 - (41.4 + 30.3) 12. 10 + 50.56 - (49 - 30.7) 13. 130 - 89 - (57.3 - 56) 14. 88.1 - 78.22 - (0.7 - 0.6) 15. 38.2 - (18.1 + 17.3 - 3.3) 16. 57.1 - (19.1 - 12.4 + 3.6) 17. $22.40 + $18.44 + $400.98 - ($15.00 + $25.88 + 22.05 + $55.69) 18. $34.66 + $19.03 + $510.89 - ($25.00 + $34.77 + 52.06 + $51.22) Making Sense of Numbers Unit 3 Decimals 99 NAME CLASS DATE Multiplying Decimals UNIT 3 OBJECTIVE: Finding the product of two decimals Multiplying two decimals is similar to multiplying whole numbers. The following examples will show you where to place the decimal point in the product. Multiply: 6.33 X 7 EXAMPLE 1 Soluti n 6.33 7 44.31 two decimal places X two decimal places Thus, 6.33 X 7 = 44.31. If both decimals have digits to the right of the decimal point, the product will have as many decimal places as the sum of the numbers of places in the given decimals. FINIMIN-MILLMO I EXAMPLE 2 Multiply: 4.25 X 3.6 Solution two decimal places one decimal place three decimal places Therefore, 4.25 X 3.6 = 15.300, or simply 15.3. L 12 X 8.5 2. 6.3 X 9 3. 12 X 3 6 4. 125 X 4.8 5. 124 X 3.1 6. 256 X 8 4 7. 1.5 X 2.5 8. 3.5 X 3.5 9. 4.4 X 3 2 10. 7.2 X 0.6 11. 0.3 X 11.6 12. 0.7 X 08 13. 17.2 X 3.65 14. 1.72 X 9.7 15. 8.68 X 1 7 16. 0.24 X 0.48 17. 0.65 X 0.65 18. 12.35 X 5.34 102 Unit 3 Decimals Making Sense of Numbers Copyright © by Holt, Rinehartand Winston. Allrightsreserved. 4.25 X 3.6 255 1275 15.300 DATE CLASS NAME V dung Decimals OBJECTIVE: Dividing a decimal by another decimal To divide with decimals, transform the decimal division into a wholenumber division. When dividing by a whole number, place the decimal point in the quotient directly above the decimal point in the dividend. When dividing by a decimal, move the decimal point in the divisor and the dividend enough places to make the divisor a whole number. Then divide as with a whole-number divisor. Divide. a. 84.7 ± 7 b. 11.96 ± 2.3 Solution 12.1 a. 7)84.7 7 14 14 7 7 5.2 b. 2.3)11.96 --> 23)119.6 115 46 46 0 Copyright ©by Ho lt, Rinehart andWinston. Al l rights reserved. So, 84.7 ± 7 = 12.1. So, 11.96 ± 2.3 = 5.2. Divide. 1. 42.5 ± 5 2. 72.18 ± 6 3. 213.3 ± 9 4. 530.4 ± 8 5. 1266.9 ± 3 6. 1863.5 ± 5 7. 85.2 ± 12 8. 55.5 ± 15 9. 223.2 ± 18 10. 124.8 ± 12 11. 235.3 ± 13 12. 355.3 ± 17 13. 2.55 ± 1.5 14. 32.66 ± 2.3 15. 33.92 ± 6 4 16. 35.88 ± 2.6 17. 91.98 ± 7.3 18. 129.05 ± 8 9 19. 121.33 ± 1.1 20. 204.96 ± 6.1 21. 509.74 ± 7 7 22. 240.45 ± 10.5 23. 452.6 ± 12.4 24. 1024.88 ± 18 4 Making Sense of Numbers Unit 3 Decimals 111 Grade Answer Key Compare your solutions to the answers as you work through the packet to check your understanding. MATHEMATICS is not about numbers, equations, computations, or alorithms: it is about UNDERSTANDING. yt)A4,m pa A,“)otohi 142)\-\t-el-vay, CHAPTER 1 Order of Operations 1. 18 2. 24 3. 29 4. 12 5. 12 6. 30 7. 96 8. 4 9. 23 10. 32 11. 4 12. 70 13. 26 14. 36 15. 20 16. 78 17. 40 18. 10 1. 351 2. 232 3. 38 4. 122 5. 256 6. 864 7. 1000 8. 9261 1. 9 2. 116 3. 4 4. 410 5. 72 6. 9 7. 165 8. 2 9. 35 10. 18 11. 129 12. 44 13. 24 14. 160 15. 53 16. 51 17. 107 18. 28 19. 16 20. 17 CHAPTER 3 Fraction Fundamentals 2. 31. 12 = To 2 4 = 3 12 A Ft. -4 = 13 7 _ 28 5' 3 -12 9 18 6. .3 = 10 6 3 7' 7 = 14 & 65=20 24 20 - 35 9 _ 63 10. - 56 13 _ 78 11. • 54 15 _ 120 12. ▪ - •48 6 = 78 13. 7 91 11 _ 132 14. 8 -•96 17 _85 15. Ti - 60 6 = 4 1 -= 12 9 3 3'12 = i 4 2 4. .17 = 20_S 164 15 6. 30 _ 84 36_6 9' 54 6 = 36 32 16 11. = -171 u. 24 8 yo60 36 3 13. Ti =i 12. 14. 15' U. 81_9 71.3 6 51 - 6 110 10 =T 175 _ 7 -36- CHAPTER 4 Addition of Fractions and Mixed Numbers 9 2. 11 11. 1 3 3. -4 5. 34 4 12. , or 11 3 3 8 13. 9 2 9 14. 7, or 17 2 U. 3 15. 2 2 4. 3 7. 11 2 9. 2 1 -24 IT o r 2 7 1 4 17. 3, or 13 8. 1 5 16. 2 3, or 13 18. 11 23 11 . T) 3. 29 12. 45 3 1 13. 1, or 11- 13 15 9 1 2. -, or 113- or 10. 3 1. 5 or tg -67-, or 1,1g 4 5 5. 7 12 12 6. -. 31 , 11 14. y, or iyo.) 17 1 15. 5 7. i -9- 17. 4 8. 1-5- 41 18. N 5 9. 29 Ti, or ,IN 19. 119, or 1T-9-0 7._ 1 4_, or _14 1 20. h5, or 1-i j 4. 25 1 16. ri, or 2E . 31 ,1 t-j, or I-55 11. 13 2. 4 3 3. 54 1 4. 93 12. 8 13. 7 2 5 4. 107 17 5. 35. 13 6. 430 4 14. 7T3 2 15. 18-5 5 16. 173 7. 31 8 17. 16 8. 53 18. 157 5 9. 10 19. 113 7 10. 5 7 12. 215 13' 5-118 2 14. 745 7 15. 1412 13 16' 540 17. ' 30 18. 1018. 2103 5 19. 158 1 20. 162 7 21. 510 7 22. 188 4 23. 165 1 2 24. 12- CHAPTER 5 Subtraction of Fractions and Mixed Numbers 19 10. 1 -6 13 10. -4-i ' 2 4. 5. 3. 12. To- 4. 1. 3 14. 2 1 15. 3 5 5. .1-47 6. T8- 14. 16. 0 • 1 17. 3 18. To 7. 13 • 1 & 24 5 7 1 6. 3 7. 3 U. 7 31 11. 12: 1.1 20 4 7 5' 3-8 1 6. 4-i 9. 35- 1 18. 9-4 1 3 15. -4 1 16. -§ 2 17. 3 1& 15 CHAPTER 6 Multiplication of Fractions and Mixed Numbers 21 1. -43 5 2. -6- 12. 35 1 24 6 3. 55 8 4. 21 13. 2. 5. 6. 7. a. 9. 10. 11. 1 1 2 15. 5 5 16. 9 7 17. 70 6 18. 33 9 45 1 . 3; 5 1 20. 1., or 21 40 19 21. IT, or 1H 136 6 29 12 12. 107 13. yes 2. 3. 3 14 1 12 1 50 9 21. 22. 49 1 49 1 15 3 14. T5, or 15. 7 1, - or 3i 16. 28 MO 17. 3-, or 335 8. .2 18. 144 9. 28 19. 40 1 .1 10 5 21 27 23. 1 3. 2 4. 1 15. no 19 1 24. T, or 65 3 25. B- 1 5. 3 6. 200 16. yes 26. 1 6. 3 7. none 17. no 27. 13 1 '7. 3 4. 5. 8. 1 7 9. 15 10. 46 14. yes 18. no 19. 1 20. 4 1 7. 3 10. 48 2.. 1 13. -i, or 83 CHAPTER 7 Division of Fractions and Mixed Numbers 11. 1 12. -T, or 455 3. -89-, or 1-g1 21 1 4. iTy or 2Tr) 5. -34-, or , 1 8 2 6. 5, or 25 14. yi 9 3 8 1 9 1 16 3 To 2 35 10 33 63 11. T, or 3172- 11 or 27176 3 7 3 8. 7 4, or 1-4 5 1 9. -,or22 2 6 1 10. 3, or 1-5- 12. 6 15 T, or 1-87 13. 8 14. 1 36 15. 3 17,1 16. 5 49 17. 12 1 18. 18 19. 12 32 2 20. or 10' CHAPTER 8 Decimal Fundamentals 1. 123.45 2. 123.5 3. 0.3 4. 0.54 5. 20 6. 8 7. 3.14 8. 1.4 9. 0.005 10. 0.1 11. 18 12. 4 CHAPTER 9 Addition and Subtraction of Decimals 1. 31.7 2. 16 3. 43.4 4. 65.8 5. 44.34 6. 22.08 7. 95.45 8. 50.95 9. 60.9 10. 202.34 11. 64.57 12. 102.74 13. 108.4 14. 169.65 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 3.3 0.1 0.05 17.9 1.56 4.08 1.69 1.38 1 0.02 0.27 4.1 9-9 1. 27.2 2. 11.68 3. 3.3 4. 154.2 5. 25.57 6. 45.4 7. 0.19 8. 0.16 9. 60.56 10. 111.2 11. 39.47 12. 42.26 13. 39.7 14. 9.78 15. 6.1 16. 46.8 17. $323.20 18. $401.53_ CHAPTER 10 Multiplication of Decimals •1. 102 2. 56.7 3. 43.2 4. 600 5. 384.4 6. 2150.4 7. 3.75 8. 12.25 9. 14.08 10. 4.32 11. 3.48 12. 0.56 13. 62.78 14. 16.684 15. 14.756 16. 0.1152 17. 0.4225 18. 65.949 CHAPTER 11 Division of Decimals 11-2 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 8.5 12.03 23.7 66.3 422.3 372.7 7.1 3.7 • 12.4 10.4 18.1 20.9 1.7 14.2 5.3 13.8 12.6 14.5 110.3 33.6 21. 22. 23. 24. 66.2 22.9 36.5 55.7