170 Rational NumbersWOODWORKING Students in a woodworking814 in.class are making butterfly houses. The side
pieces of the house need to be 8 _^1
4
inches
long. How many side pieces can be cut
from a board measuring 49 _^1
2
inches long?
To find how many side pieces can be cut,
divide 49 _^1
2
by 8 _^1
4
.
Estimate Use compatible numbers. 48 ÷ 8 = 6
49 _^1
2
÷ 8 _^1
4
= _^99
2
÷ _^33
4
Rename the mixed numbers as fractions greater than one.= _^99
2
· _^4
33
Multiply by the reciprocal of _^334 , which is _ 334.
3
/2
= _^99 /
2
· _^4
33
Divide out common factors.
1/ / 1
= _^6
1
or 6 Multiply.
So, 6 side pieces can be cut.
Check for Reasonableness Compare to the estimate. 6 = 6 ✓h. FOOD Suppose a small box of cereal contains 12 _^2
3
cups of cereal.
How many 1 _^1
3
-cup servings are in the box? Write in simplest form.i. MEASUREMENT The area of a rectangular bedroom is 146 _^7
8
square
feet. If the width is 11 _^3
4
feet, find the length in simplest form.Examples 1 and 2 Divide. Write in simplest form.
81 ÷ 31 2. - ^35 ÷ (^) (- 41 ) 3. - 3 ÷ (- ^67 ) 4. ^34 ÷ 6
55 ^12 ÷ 7 ^12 6. 74 ÷ (- 1 (^27) ) 7. 5 53 ÷ 4 ^23 8. 6 ^12 ÷ 3 ^57
Example 3 9. FOOD Deandre has 7 apples and each apple
is divided evenly into eighths. How many
apple slices does Deandre have?
WALKING On Saturday, Lindsay walked
3 ^12 miles in 1 ^25 hours. What was her
walking pace in miles per hour? Write
in simplest form.
168_173_C3L3_895130.indd 170 12/31/09 12:44 PM