Measuring in Customary Units in Customary Units You measured and estimated ... Your mass is the same wherever you are, but your weight depends on gravity. On the moon, for instance,

230 Chapter 5 Fraction Operations

Word WatchU.S. customary system,

p. 230 length: inch, foot, yard,

mile, p. 230weight: ounce, pound, ton,

p. 231capacity: fluid ounce, cup,

pint, quart, gallon, p. 232

B E F O R E Now W H Y ?

Measuring in Customary Units

You measured and estimatedusing metric units.

You’ll measure and estimateusing customary units.

So you can estimate the weight ofan elephant, as in Ex. 22.

The units of measurement for length, weight, and capacity commonlyused in the United States are part of the .

Length The is a unit of length in the customary system.

Three other customary units of length are the , ,

and . You can use the following benchmarks to estimate length.

1 inch 1 foot 1 yard

length of a distance from width of a doorsmall paper clip shoulder to elbow

1 mile combined length of 15 football fields

mile (mi)yard (yd)foot (ft)

inch (in.)

U.S. customary system

E X A M P L E 1 Using Customary Units of Length

To estimate the length of a barrette, think of small paper clips laid next toit. Then measure the barrette with a ruler to check your estimate.

About 1 �12

� paper clips fit The ruler shows sixteenths

alongside the barrette, so of an inch, so the barrette is

it is about 1 �12

� inches long. 1 �11

46�, or 1 �

78

�, inches long.

Lesson 5.5 Measuring in Customary Units 231

Weight The weight of an object tells you how heavy the object is. Threecustomary units of weight are the , , and

. You can measure the weight of an object using a scale.ton (T)pound (lb)ounce (oz)

with Reading

Be careful to distinguishbetween mass and weight.Your mass is the samewherever you are, but yourweight depends on gravity.On the moon, for instance,

you would weigh about �16

�

of what you weigh onEarth.

You can use the following benchmarks to estimate weight.

1 ounce 1 pound 1 tonslice of bread soccer ball walrus

E X A M P L E 3 Using Customary Units of Weight

Copy and complete the statement using the appropriate customaryunit: The weight of a bowling ball is 14 _?_.

The weight of a bowling ball is greater than the weight of 14 slices ofbread (14 oz), and it is certainly less than the weight of 14 walruses (14 T). Because a good estimate for the weight of a bowling ball is theweight of 14 soccer balls, the appropriate customary unit is pounds.

ANSWER The weight of a bowling ball is 14 pounds.

Complete the following exercises.

1. Estimate the length of an unsharpened pencil in inches. Then use aruler to check your estimate.

2. The weight of a baseball bat is 33 _?_.

Your turn now

E X A M P L E 2 Measuring Weight

Find the weight of the bananas.

ANSWER The bananas weigh 1 �78

� pounds.

Each pound is divided into sixteenths, so

the arrow is at the 1 �11

46� lb or 1 �

78

� lb mark.

1lb

2lb

3lb

4lb

5lb6lb

7lb

8lb

9lb0lb

1lb

2lb

3lb

4lb

5lb

0lb

1lb

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b0lb

232 Chapter 5 Fraction Operations

Capacity Capacity is a measure of the amount that a container canhold. Five customary units of capacity are the ,

, , , and .gallon (gal)quart (qt)pint (pt)cup (c)fluid ounce (fl oz)

A fluid ounce isnot the same as an ounce.Fluid ounces are a measureof the capacity of acontainer holding liquid,while an ounce measuresthe weight of the container.

Watch Out!

E X A M P L E 4 Measuring a Liquid Amount

Find the amount of liquid in the measuring cup.

ANSWER There are about 3 �34

� cups of liquid in the measuring cup.

You can use the benchmarks shown to estimate capacity.

E X A M P L E 5 Using Customary Units of Capacity

What is the most reasonable capacity of a lemonade pitcher?

A. 8 fl oz B. 2 qt C. 10 gal D. 3 c

Solution

Both 8 fluid ounces and 3 cups of water are too little to fill the pitcher. A pitcher couldn’t hold more than a gallon, so 10 gallons is too much.That leaves 2 quarts of water, which seems an appropriate capacity.

ANSWER The most reasonable capacity of a lemonade pitcher is (B) 2 qt.

Match the object with the appropriate capacity.

3. Juice glass 4. Paint can 5. Ice cube tray

A. 1 gal B. 1 pt C. 7 fl oz

Your turn now

Each cup is divided into fourths,

so the liquid is at the 3 �34

� cup level.

1 fluid ounce

Lesson 5.5 Measuring in Customary Units 233

Estimate the length of the object in inches. Then measure theobject using a ruler.

7. Your shoe 8. Calendar 9. Picture frame

Find the weight of the object.

10. 11.

Find the amount of liquid in the measuring cup.

12. 13.

Copy and complete using the appropriate customary unit.

14. Mount Everest is 5 �12

� _?_ high. 15. A tennis racket weighs 20 �12

� _?_ .

16. A shampoo bottle holds 12 _?_. 17. A teakettle holds 5 _?_ .

Tell what measurement tool would be appropriate for the given unit.

18. fluid ounce 19. inch 20. pound

1lb

2lb

3lb

4lb

5lb6lb

7lb

8lb

9lb0lb

1lb

2lb

3lb

4lb

5lb

0lb

1lb0lb

1lb

2lb

3lb

4lb

5lb6lb

7lb

8lb

9lb0lb

1lb

2lb

3lb

4lb

5lb

0lb 4lb

5lb

Practice and Problem Solving

1. Vocabulary Which unit measures capacity: yard, cup, or pound?

Copy and complete using the appropriate customary unit.

2. A dictionary is 2 �12

� _?_ thick. 3. A marathon is 26 �15

� _?_ long.

4. A stapler weighs 8 _?_. 5. A swimming pool holds 15,000 _?_.

6. Sunglasses Dave thinks that the weight of a pair of sunglasses is 7 oz.Mary thinks that the weight is about 2 lb. Who is right? Explain.

Getting Ready to Practice

ExercisesMore Practice, p. 709

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Example Exercises1 7–9, 14–17, 21–222 10–113 14–17, 21–224 12–135 14–17

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234 Chapter 5 Fraction Operations

In Exercises 21 and 22, choose the letter of the most reasonablemeasurement.

21. Travel What is the distance between Austin, Texas, and Tallahassee, Florida?

A. 1760 yd B. 7000 ft C. 600 in. D. 800 mi

22. Elephants What is the weight of an Indian bull elephant?

F. 3 �12

� T G. 600 lb H. 2000 oz I. 100 lb

23. Critical Thinking If one scale has each pound divided into fourths andanother scale has each pound divided into halves, which scale will giveyou a more precise measurement? Explain your reasoning.

Tell whether an exact answer or an estimate is needed for thegiven situation.

24. Sawing wood to build a deck 25. Distance from home to the park

26. The amount of weight you lost 27. Your finish time in a track race

28. Challenge Is it possible for two containers, when filled, to have thesame weight but different capacities? If so, give an example. If not,explain why not.

33. Multiple Choice What is a reasonable capacity for a fish aquarium?

A. 18 fl oz B. 7 pt C. 16 qt D. 14 gal

34. Multiple Choice Which is the greatest length?

F. 30 in. G. 3 ft H. �12

� mi I. 1 yd

Test-Taking Practice

Choose a Strategy Use a strategy from the list to solve the following problem. Explain your choice of strategy.

29. Jackie, Sean, Tim, and Katie have four seats in a row at a basketball game. In how many different ways can they sit?

Copy and complete the statement.

30. 120 min � _?_ h 31. 90 sec � _?_ min 32. 3 wk � _?_ d

Basic Skills

Mixed Review

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Problem Solving Strategies■ Make a List■ Estimate■ Look for a Pattern

■ ElephantsAn Indian bull elephant’sfootprint has a width of

about 1 �12

� feet. How many

of your footprints would fitacross the footprint of anIndian bull elephant?

Science