Page 434 - Basic College Mathematics with Early Integers

S E C T I O N 5.6 I CAPACITY: U.S. AND METRIC SYSTEMS OF MEASUREMENT 411

Example 2 Convert 14 cups to quarts. PRACTICE 2
Convert 26 quarts to cups.
Solution: Our equivalency table contains no direct conversion from cups to
quarts. However, from this table we know that
2 pt 2 pt 2 c
1 qt = 2 pt = # 1 = # = 4 c
1 1 1 pt
1 qt
so 1 qt = 4 c. Now we have the unit fraction . Thus,
4 c
14 c 14 c 1 qt 14 qt 7 1
14 c = # 1 = # = = qt or 3 qt
1 1 4c 4 2 2

+ + + 14 cups
3q qt
1 quart 1 quart 1 quart q quart
Work Practice 2

Concept Check If 50 cups is converted to quarts, will the equivalent num-
ber of quarts be less than or greater than 50? Explain.
Objective Performing Operations on U.S.
System Units of Capacity

As is true of units of length and weight, units of capacity can be added, subtracted,
multiplied, and divided.

Example 3 Subtract 3 qt from 4 gal 2 qt. PRACTICE 3
Subtract 2 qt from 1 gal 1 qt.
Solution: To subtract, we line up similar units.
4 gal 2 qt

- 3 qt
We cannot subtract 3 qt from 2 qt. We need to borrow 1 gallon from the 4 gallons,
convert it to 4 quarts, and then combine it with the 2 quarts.

3 gal+ 1 gal 4 qt
4 gal 2 qt = 3 gal 6 qt
– 3 qt = – 3 qt
3 gal 3 qt
To check, see that the sum of 3 gal 3 qt and 3 qt is 4 gal 2 qt.
Work Practice 3

Example 4 Divide 3 gal 2 qt by 2. PRACTICE 4
Divide 7 gal 2 qt by 3.
Solution: We divide each unit of capacity by 2.

1 gal 3 qt
23 gal 2 qt
- 2 Answers
1 gal = 4 qt Convert 1 gallon to 4 qt and add to 2 qt before continuing. 2. 104 c 3. 3 qt 4. 2 gal 2 qt
6 qt 6 qt , 2 = 3 qt
Concept Check Answer
Work Practice 4 less than 50; answers may vary