Lesson 10-6
Key Idea
We use special
units to tell how
much liquid a
container will hold.
Customary Units of
Capacity
Multiply or divide.
2
1. 3 ⴛ 7ᎏ3ᎏ
23
3
2. 8 ⴛ 1ᎏ4ᎏ
14
3. 18 ⴜ 12 4. 12 ⴜ 18
Vocabulary
• capacity
• teaspoon
• tablespoon
• fluid ounce
• cup
• pint
• quart
• gallon
1
How can you measure liquid?
Capacity is a measure of an
amount of liquid. Many
different units can be used to
measure capacity.
A common measuring device
for capacity is a measuring
cup, but many other devices
can be used.
3. 1ᎏ2ᎏ
2
4. ᎏ3ᎏ
Data File
Unit
teaspoon (tsp)
Relationship
1
1 tsp ⫽ ᎏ3ᎏ tbsp
tablespoon (tbsp)
fluid ounce (fl oz)
cup (c)
pint (pt)
quart (qt))
gallon (gal)
1 tbsp ⫽ 3 tsp
1 fl oz ⫽ 2 tbsp
1 c ⫽ 8 fl oz
1 pt ⫽ 2 c
1 qt ⫽ 2 pt
1 gal ⫽ 4 qt
Example A
Example B
■ gal ⫽ 10 qt
4 qt 1 pt ⫽ ■ pt
Think: 1 gal ⫽ 4 qt
Think: 1 qt ⫽ 2 pt
10 ⫼ 4 ⫽ 2 R2
1
10 qt ⫽ 2 gal 2 qt or 2ᎏ2ᎏ gal
(2 ⫻ 4) + 1 ⫽ 8 + 1
4 qt 1 pt ⫽ 9 pt
You can add and subtract units of capacity just as you
can add and subtract units of length.
Example C
Example D
5 gal 1 qt ⫽ 4 gal 5 qt
⫺3 gal 3 qt ⫽ ⫺3 gal 3 qt
ᎏᎏᎏᎏᎏ
ᎏᎏᎏᎏᎏ
1 gal 2 qt
3 pt 1 c
⫹3 pt 1 c
ᎏᎏᎏᎏ
6 pt 2 c
7 pt
Think: 2 c ⫽ 1 pt
Add 1 pt to 6 pt.
1. When you divide 10 by 4, the quotient is 2 R2 which means there
are 2 gallons with 2 quarts remaining. Since 2
Talk About It
2
1
quarts is ᎏ4ᎏ of a gallon, you could also write 2ᎏ2ᎏ
1
1. In Example A, why is 2 R2 equal to 2 gal 2 qt or 2ᎏ2ᎏ gal? gallons.
See above.
2. In Example C, why do you change 5 gal 1 qt to 4 gal 5 qt?
Because you cannot subtract 3 qt. from 1 qt.
3. Reasoning Which unit (or units) of capacity would be reasonable
to measure each capacity? Sample answers are given.
a. milk carton
d. drinking glass
614
a. quarts or gallons
d. fluid ounces
or cups
b. medicine bottle
e. thimble
b. fluid ounces
e. teaspoons
c. car’s gas tank
f. swimming pool
c. gallons
f. gallons