Page 424 - Basic College Mathematics with Early Integers

S E C T I O N 5.5 I WEIGHT AND MASS: U.S. AND METRIC SYSTEMS OF MEASUREMENT 401

9000 lb 9000 lb 1 ton 9000 tons 9 1
9000 lb = # 1 = # = = tons or 4 tons
1 1 2000 lb 2000 2 2
2000 lb 2000 lb 2000 lb 2000 lb 1000 lb

9000 lb
4q tons

1 ton 1 ton 1 ton 1 ton q ton
Work Practice 1

Example 2 Convert 3 pounds to ounces. PRACTICE 2

16 oz Convert 72 ounces to pounds.
Solution: We multiply by the unit fraction to convert from pounds to ounces.
1 lb
3 lb 3 lb 16 oz
#
3 lb = # 1 = # = 3 16 oz = 48 oz
1 1 1 lb
1 pound 1 pound 1 pound

3 lb 48 oz

16 ounces 16 ounces 16 ounces

Work Practice 2
As with length, it is sometimes useful to simplify a measurement of weight by
writing it in terms of mixed units.

Example 3 Convert: 33 ounces = _____ lb _____ oz PRACTICE 3
Convert:
Solution: Because 16 oz = 1 lb, divide 16 into 33 to see how many pounds are in
47 ounces = _____ lb _____ oz
33 ounces.The quotient is the number of pounds, and the remainder is the number
of ounces.To see why we divide 16 into 33, notice that
1 lb 33
#
33 oz = 33 oz = lb
16 oz 16
2 lb 1 oz
16 33
– 32
1
Thus, 33 ounces is the same as 2 lb 1 oz
16 ounces 16 ounces 1 ounce

33 oz
2 lb 1 oz

1 pound 1 pound 1 ounce
Answers
Work Practice 3
1
2. 4 lb 3. 2 lb 15 oz
2