Changing Units in
the Customary
System
Lesson 5-8
Strategy
• When converting from a large unit to a
small unit, multiply by the conversion
factor.
• When converting from a small unit to a
larger unit, divide by the conversion
factor.
Small - - - - - - - - Large
Inch (in) ---------- Foot (ft)-------- Yard (yd) ------- Mile (mi)
Ounce (oz) -------------- Pound (lb) -------------Ton (t)
Fluid Ounce (fl. oz.) -- Cup (c) -- Pint (pt) -- Quart (qt) -- Gallon (gal)
Changing Units
• Determine the direction of the change
(LS or SL)
• Multiply or Divide by the appropriate
conversion unit.
Example
48
12 gal = ______
qt
LS
12 x 4
(1 gal = 4 qt)
Example 2
40 in = ______ ft
SL
40 ÷ 12
1
1
10 40 x 1
1
12 3
10
3
=
3
We can divide fractions so
that remainders can be
described as fractions.
1
3
Computing With Units
• Combine or subtract like units.
• Regroup.
19
7 8 feet 7 inches
-
5 feet 11 inches
2 feet 8 inches
1 foot = 12 inches
Homework Time