628 Measurement and Proportional ReasoningTo convert from smaller units to larger units, multiply by the
reciprocal of the appropriate unit ratio.Convert Smaller Units to Larger Units
Convert 15 quarts to gallons.
Since 1 gallon = 4 quarts, the unit ratio is4 qt
_1 gal , and its reciprocalis1 gal
_4 qt.15 qt = 15 qt ·1 gal
_4 qt Multiply by
1 gal
_4 qt.= 15 qt ·1 gal
_4 qt^ Divide out common units, leaving the desired unit, gallons.= 15 · ^14 gal or 3.75 gal Multiplying 15 by ^14 is the same as dividing 15 by 4.
COSTUMES Umeka needs 4 _^12 feet of fabric to make a costume for a
play. How many yards of fabric does she need?4 21 ft = 4 ^12 ft ·
1 yd
_3 ft Since 1 yard = 3 feet, multiply by1 yd
_3 ft. Then, divide out
common units.
3
= _^92 · _^13 yd Write 4_^1
2 as an improper fraction. Then divide out
1 common factors.= ^32 yd or 1 ^12 yd Multiply.
So, Umeka needs 1 _^12 yards of fabric.
Complete.
e. 2,640 ft = mi f. 100 oz = lb g. 3 c = pth. FOOD A 3-pound pork loin can be cut into 10 pork chops of
equal weight. How many ounces is each pork chop?Examples 1 and 2 Complete.- 3 lb = oz 2. 5 _^1
3
yd = ft 33 6.5 c = fl oz - FISH A large grouper can weigh _^1
3
ton. How much does a large grouper
weigh to the nearest pound?
Examples 3 and 4 Complete. - 12 qt = gal 6. 28 in. = ft 7. 15 pt = qt
- VEHICLES The world’s narrowest electric vehicle is about 35 inches wide.
How wide is this vehicle to the nearest foot?
Reciprocal The product
of a number and its
reciprocal is 1. For
example, the reciprocal
of _ 5 3 is _^53.624_630_C11_L1_895130.indd 628 12/31/09 9:36 AM