Chapter 3 answers click to jump to a section

1
Chapter 3 answers (click to jump to a section)

• 3-1 Rounding and Estimating
• 3-2 Estimating Decimal Products and Quotients
• 3-3 Mean, Median, and Mode
• 3-4 Using Formulas
• 3-5 Solving Equations by or Decimals
• 3-6 Solving Equations by x or Decimals
• 3-7 Using the Metric System
• 3-8 Reasoning Strategy Simplify a Problem

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3-1 Rounding Estimating pg. 125-126

• 27.39
• 0.912
• 1,046
• 345.7
• about 11
• about 19
• about 45
• about 13.90
• about 10
• about 20.7

• about 129
• about 27
• about 0.60
• Answers vary
• 1.5
• 4,652.99
• 1
• 33.30
• about 9
• about 11

• about 28
• about 150
• about 4
• about 400
• about 17
• about 43
• about 93.5
• about 53.90
• about 90.4
• about 484.60

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3-1 Rounding Estimating pg. 125-126

• about 9.5
• about 10.5
• about 10.1
• about 10.8
• about 28
• about 80
• about 3,200
• about 220

• 3946. Answers may vary. Samples are given.
• about 17 rounding
• about 9.2 front-end
• about 40 rounding
• about 25 rounding
• about 20 rounding
• about 10 rounding
• about 27.50 front-end
• about 24 clustering

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3-1 Rounding Estimating pg. 125-126

• about 3.4 million
• about 22,000 mi2
• about 44 in.
• Subtract 219 instead of 2.19.
• Answers will vary. Sample front-end it gives
  an estimate of 11.80, so I dont have enough
  money.

• B
• x 3
• x lt 4

• k lt 4
• y 3
• 4

• 12
• 30
• 4

• 7 bikes 3 trucks

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3-2 Estimating Decimal Products Quotients pg.
129 - 130

• about 35
• about 44
• about 54
• about 100
• about 2
• about 2
• about 20
• about 50

• about 18,000
• about 40
• about 4,500
• about 144
• about 120
• about 400
• about 36,000
• about 64

• about 24
• about 5
• about 5
• about 4
• about 3
• about 6
• about 7
• about 4

• Answers may vary. Sample 14.90 is about 15, and
  4.56 is about 5, so 14.90 4.56 15 5, or 3.

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3-2 Estimating Decimal Products Quotients pg.
129 - 130

• reasonable
• not reasonable
• not reasonable
• not reasonable

• reasonable
• not reasonable
• Check students work.
• about 12
• C

• Answers may vary. Sample No. 2 9 18 will
  give one estimate. A closer estimate is (2 8)
  (2 0.5) 16 1 17.
• No. 14.95 4 15 4 60. The total,
  77.80, is too far from this estimate.

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3-2 Estimating Decimal Products Quotients pg.
129 - 130

• Physical therapist about 18/h in Dallas, about
  16/h in Washington, DC pharmacist about 20/h
  in Dallas, about 21/h in Washington, DC nurse
  about 15/h in Dallas, about 18/h in Washington,
  DC.
• Physical therapist about 35,000 in Dallas and
  in Washington, DC pharmacist about 40,000 in
  Dallas and 45,000 in Washington, DC nurse
  about 30,000 in Dallas and 35,000 in
  Washington, DC.
• About 2

• About 300 L

• Answers vary.

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3-2 Estimating Decimal Products Quotients pg.
129 - 130

• About 9
• About 39
• About 20
• About 1,220
• About 12
• About 2
• Quadrant I

• Quadrant III
• Quadrant IV
• y-axis
• Quadrant III
• x-axis
• 720 PM

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11
3-3 Measures of Central Tendency, Mean, Median
Mode pg. 134 - 135
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3-3 Mean, Median, Mode pg. 134 - 135
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3-3 Mean, Median, Mode pg. 134 - 135
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3-3 Mean, Median, Mode pg. 134 - 135

• D
• a. 8,4g
• b. 93.5 calories
• a.b. check students work
• 49.4g, 574 calories
• about 6
• about 720

• about 6
• about 39.00
• 6x 10
• 4x 8z
• x 2t 5
• 80 adults hats

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3-4 Using Formulas, pg. 139 -140

• 67F
• 57F
• 60F
• 53F
• d 481.25 m
• r 280 mi/h
• t 259.3 s
• t 20.4 h
• 5.84 mi

• 136.4F
• 57.2F
• -128.2F
• 132.8F
• 161.6F
• 21 m
• 74 m
• 43.2 yd

• 24.5 m2, 288.96 m2, 93.6 yd2

• a. 701.32 ft2

• b. 358.66 ft
• 105,300 mi2
• 0.425 mi
• a. 36F 40F 80F

• b. see answer book

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3-4 Variables and Equations, pg. 139 - 140

• 106 min, 123 min, 125 min median
• 306 mL, 303 mL, 250 mL
• 33
• -13
• 56
• B

Check Point

• 15.66
• 0.891
• 7,023
• 345.7
• about 32
• about 24

• about -1
• about 6
• 56, 57, no mode
• 2, 2, 1
• 4.05, 2.25, no mode
• B

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3-5 Solving Equations by or Decimals, pg.
144-145

• 1.2, 1.2, x 13.8
• 3.33, 3.33 y 15.75
• Subtract 8.5 from each side or add -8.5 to each
  side.
• Subtract 54.2 from each side or add -54.2 to each
  side.
• Add 1.9 to each side

• 3.54
• 0.88
• 10.73
• 23.7
• 43.2
• -0.8
• see below

• No, the solution of the first equation is -0.9,
  while the solution of the second equation is -9.

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2-5 Solving Equations by adding or subtracting,
pg. 87-88

• 1.2
• 1.1
• 11
• -5.3
• 15.4
• 26.1
• 2.4
• 7.285
• 0

• -0.08
• -23.95
• -7.91
• 1.1
• -94.2
• 9.502
• 16.093
• 5.3
• -10.5

• Commutative Prop. of Add.
• Simplify
• Subtraction Prop. of Equality
• Simplify
• The student should have added 1.6 to each side.
• b
• Add -1.8 to each side.
• a. 5.25 b. Answers vary.
• 369.72 in2
• 38.5 cm2
• 4
• -30

• -9
• 13
• 1.30

• Simplify
• Subtr. Prop. of Equality
• Simplify

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3-6 Solving Equations by or Decimals, pg.
148-149

• 0.8, 0.8, x 1.875
• 4.5, 4.5 d -13.5
• Divide each side by 0.9
• Multiply each side by 0.6
• Multiply each side by 15
• Divide each side by -0.4

• 1.46
• 0.56
• -11.04
• -1.94

• a. Harry multiplied by 4 instead of dividing each
  side by 4. b. Answers may vary. Sample He could
  have compared his result, 324.8, to the estimate
  81.2 4 20.

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3-6 Solving Equations by or Decimals, pg.
148-149

• -2.44
• -25.1
• 0.044
• 2.3
• 1.2
• 30
• 8.6
• 1.3
• 0.374
• 0.0804
• -14.85

• 0.9912
• -5.4
• 3,104.32
• 86.7
• 456
• 4
• 13.5
• -708
• 0.048308
• -7.3n 30.66 -4.2
• N (-4.5) 200.6 -902.7

• N (--2.35) 400.9 -942.115
• a. f 3.28 l
• b. 24.6 ft
• c. about 1.83 m
• d. 16.7 m2
• 24 (or 25) onions

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3-6 Solving Equations by or Decimals, pg.
148-149

• a. 20 hits
• b. You can have only a whole number of hits.
• x 0.6, y 0.7
• (or x 0.7, y 0.6)
• -5.3
• 15.4
• 26.1
• 2.4
• 7.285
• -2

• Yes
• No
• No
• a. 2,376, 2,475
• 2,574
• b. Answers vary. Sample 99 times a number
  is 100 times the number less one of the number.
• c. 2,673

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3-7 Using the Metric System, pg. 153-155

• C
• F
• B
• E
• A
• D
• 5,400
• 0.234
• 0.012
• 3,010
• 5.18 m

• Gram a banana is well under a kilogram, so
  kilograms are too large.
• Meter the depth is less than a kilometer, so
  kilometers are too large.
• Centimeter the length is much less than a meter
  and much more than a millimeter, so meters are
  too large and millimeters are too small.
• Kilogram a car is very heavy, so grams are too
  small.
• Meter the width is much less than a kilometer
  and much more than a centimeter, so kilometers
  are too large and centimeters are too small.
• Millimeter a spoon holds much less than a liter,
  so a liter is too large.

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3-7 Using the Metric System, pg. 153-155

• 5 kg 5 g is about the mass of a nickel
• 2,000 mL 2,000 L is about 2,000 qt and 2,000 mL
  2 qt
• 350 g 350 mg is less than the mass of a paper
  clip
• 150 cm 150 m is greater than the length of a
  football field
• 2 km 2 m can be walked in 3 or 4 steps
• 1 g 1 mg is closer to the mass of a speck of
  sawdust

• m
• m
• cm
• 25
• 7,300

• 0.595
• 900.5
• 0.035
• 8.75
• 9.12

• 900,00
• 0.005
• 1,300,000
• 5.623
• 301,000,000

• E
• E
• C
• F
• A
• D

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3-7 Using the Metric System, pg. 153-155

• 6,008,835 L
• 695 m
• Camille multiplied 6,392 g by 1,000, so she
  changed grams to milligrams. To change grams to
  kilograms she should have divided 6,392 by1,000
  to find 6.392 kg.
• C
• A kilometer is 1,000 meters, a kilogram is 1,000
  grams, a milliliter is 0.001 liter, and a
  milligram is 0.001 gram.
• 0.001 53.a. 5 to 6 km b. 5,000 to
  6,000 m

• 3.068 kg
• 3.048 m

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3-7 Using the Metric System, pg. 153-155

• about 7
• about 90
• about 10
• a gt 21
• n lt -15
• r gt -7
• 6t 8.1 or
• 1.35 s/knot

• 0.25
• 130
• 8.55
• 1.5 m 1.5 cm is a little wider than the width of
  a thumbnail.
• 500 mL 500 L would be about 500 qt
• 0.095
• 7,650,000

• 3.05
• 6.5
• 129.6

• 0.675
• 7,100
• 9,100 g

t
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3-8 Reasoning Strategies . . ., pg. 161-162

• 107 digits
• 66 matches
• 13 triangles
• 55 squares
• 80 sketches
• 40 fence posts
• 3.25 ft
• 21 house numbers explanations vary. Sample
  There is 1 single-digit number that has a 5. The
  two-digit numbers have 9 numbers in the 50s.
  From 100 to 120, there are 2 numbers that have a
  5. In all, there are 1 9 9 2 21 numbers
  that contain at least one digit 5.

• 1,320 pieces 10. 3
• about 3,095 people/mi2
• 24 greetings
• 0.27
• 5,200,000
• 2
• 500

• 300
• 6,000,000
• About 46.50
• About 10.80
• 91

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