179
CH 31  MEASURING WEIGHT
 The Basic Facts: ounces (oz), pounds (lb), and tons
16 oz = 1 lb
2,000 lb = 1 ton
Why is pound abbreviated lb? It
comes from the Latin word libra,
which means “scales.”
The following are the four possible conversion factors in
the U.S. measurement system that we get from these
basic facts:
1 lb
16 oz
2,000 lb
1 ton
16 oz
1 lb
1 ton
2,000 lb
Each fraction equals 1
 Conversion Examples
EXAMPLE 1:
Convert 80,000 ounces to tons.
Solution: Ounces are tiny compared to tons, so we expect that
80,000 ounces will end up being a much smaller number of tons.
To get from ounces to tons, we need to pass through pounds. As
we did with the inches, feet, etc., we start by writing the given
problem over 1, followed by multiplying by conversion factors
until the only unit of measurement which remains is tons.
80,000 oz
80,000 ton
 1 lb  1 ton =
= 2.5 tons
1
32,000
16 oz 2,000 lb
Ch 31  Measuring Weight
180
EXAMPLE 2:
Convert 1.2 tons to ounces.
Solution: Tons are huge compared to ounces, so we expect that
1.2 tons will end up being a much, much larger number of ounces.
To get from tons to ounces, we need to pass through pounds:
1.2 ton
2,000 lb
16 oz


= 38,400 oz
1
1 ton
1 lb
Homework
Convert:
1.
3 tons to lb
2.
28 oz to lb
3.
0.3 lb to oz
4.
7,500 lb to tons
5.
3.9 tons to lb
6.
2.9 tons to oz
7.
20 oz to lb
8.
2.2 tons to lb
9.
1.4 tons to oz
10.
320 lb to tons
11.
12,800 oz to tons 12.
1.8 lb to oz
13.
1.5 tons to lb
14.
1.6 tons to oz
15.
2.8 lb to oz
16.
96,000 oz to tons 17.
89.6 oz to lb
18.
640 oz to tons
“Mathematics is
the music
of reason.”
Solutions
1.
6,000 lb
2.
1.75 lb
3.
4.8 oz
4.
3.75 tons
5.
7,800 lb
6.
92,800 oz
7.
1.25 lb
8.
4,400 lb
9.
44,800 oz
10.
0.16 ton
11.
0.4 ton
12.
28.8 oz
13.
3,000 lb
14.
51,200 oz
15.
44.8 oz
16.
3 tons
17.
5.6 lb
18.
0.02 ton
Ch 31  Measuring Weight
James Joseph
Sylvester