7th Grade Math

Selected Answers and Solutions R33

Selected Answers and Solutions

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V = wh Volume of a rectangular prism

= (1)(0.42)(0.83) Replace and h with 0.83. with 1, w with 0.42,

= 0.35 Simplify.

The volume of the rectangular prism is 0.35 cubic feet.

Find the volume of the triangular prism.

V = 1 _ 2 bh Volume of a triangular prism

= _^12 (1)(0.83)(0.42) Replace and  with 0.42.b with 1, h with 0.83,

= 0.17 Simplify.

The volume of the triangular prism is 0.17 cubic feet.

The volume of the entire solid is 0.35 + 0.17 or

0.5 cubic feet.

17. Sample answer:

3 × 3 × 8

d = 6 and h = 8

19. Sample answer: The area of the rectangular face
    on the half cylinder must be found, making it a
    composite shape. 21. I 23. 164.01 cm^2


20. 923.6 ft^2 27. 502.7 ft^3
    Pages 611–615 Chapter Study Guide and Review


21. rectangular prism 3. cubic 5. cone


22. multiplying 9. 14.6 m^3 11. 371.9 in^3


23. 4,042.4 km^3 15. 48.1 in^3 17. 6.3 mm^3


24. 288 cm^3 21. 377.0 in^3 23. 202 yd^2 25. 43 ft^2


25. 2,261.9 in^2 29. 168 in^2 31. 998,750 ft^2


26. $106 35. 13 m^3

Chapter 11 Measurement and

Proportional Reasoning

Page 622 Chapter 11 Are You Ready?

1.^35 3. ^14 5. 1 _^12 7. 4 acres 9. 900 11. 2,400
13. 81.5
Pages 628–630 Lesson 11-1B

1. 48
   33 Since 1 cup = 8 fl uid ounces, the unit ratio is
   _16 fl oz
   1c^.
   6.5 c = 6.5 c · 8 fl_1c oz Multiply by 8 fl oz_1c.

= 6.5 · 8 fl_ oz 1

Divide out common

units, leaving the desired

unit, fluid ounces.

= 6.5 · 8 fl oz or 52 fl oz Simplify.

So, 6.5 cups = 52 fluid ounces.

5. 3 7. 7 21 9. 6 11. 32 13. 9 15. 10,560 17. 2 21


6. 5 _^12
   2121 Since 1 ton = 2,000 pounds, the unit rate
   is 2,000 lb_1 T.

(^1)
2 T =^
^1
2 T ·^
2,000 lb_
1 T^
Multiply 2,000 lb1 T by^1 2 since you
have ^12 T.
= ^12 · 2,000 lb 1 Divide out common units, leaving the desired unit, pounds.
= 2,000 lb 2 or 1,000 lb Simplify.
So, _^12 ton = 1,000 pounds.

23. 13 yd
    2525 No; 2 +^2 + ^41 +^ 31 +^4 =^8 _ 127 c punch and a
    2-qt pitcher holds 2 qt ·
    2 pt
    _1 qt · 1 pt2 c = 2 · 2 · 2 c or 8 c.
    Since 8 c < 8 127 c, the pitcher will not hold all of the
    punch.


24. 20 29. 82.8 31. Sample answer: Annabelle is
    making brownies. The recipe calls for 2 cups of
    sour cream. She has 2 pints of sour cream. Does she
    have enough sour cream to make the brownies?


25. 
    

    
    

    ; Sample answer: 8 ^34 gal is equivalent to 35 qt,
    Since 35 qt > 32 qt, 8 43 gal > 32 qt. 35. Sample
    answer: 5 pt; 40 oz 37. B 39. D

    
    

    
    

Pages 633–634 Lesson 11-1C

1. 370 3. 1.46 5. 500,000 cm
   77 1 mm = 0.001 m Write the relationship.
   983 × 1 mm = 983 × 0.001 m Multiply each side by 983 since you have 983 mm.

983 mm = 0.983 m

To multiply 983 by

0.001, move the decimal

point 3 places to the left.

So, 983 mm ≈ 0.98 m.

9. 30 11. 0.08 13. 130,500 15. 0.51 kg 17. about
   35,000 meters per hour 19. 0.06 L, 660 mL, 6.6 kL


10. 130 cm, 2,650 mm, 5 m
    2323 First subtract to fi nd how many meters Jacinta
    needs to cut off the pole. She needs to cut off
    3 - 2.5 or 0.5 meters. Next, convert 0.5 meter to
    centimeters.
    1 m = 100 cm Write the relationship.
    0.5 × 1 m = 0.5 × 100 cm Multiply each side by 0.5
    since you have 0.5 m.
    0.5 m = 50 cm


11. Sample answer: Theresa divided 3.25 by 1,000.
    She should have multiplied; 3,250 g. 27. Sample
    answer: There are a greater number of smaller
    units. 29. H 31. eighth inch

Pages 636–638 Lesson 11-1D

1. 3.37
   33 Since 1 pound is equal to 0.4536 kg, multiply
   by _0.4536 kg1 lb.

R01_R42_EM_SelAns_895130.indd R33 1/18/10 9:51 AM