Warm Up

1

2
Warm Up Multiply.
5 6
1.
3
23
2.
10
15
3. 0.05(2.8)
0.14
4. 0.9(16.1)
14.49
3
Problem of the Day Katie made a bookshelf that
is 5 feet long. The first 6 books she put on it
took up 8 inches of shelf space. About how many
books should fit on the shelf?
45 books
4
Learn to divide fractions and decimals.
5
Vocabulary
reciprocal
6
A number and its reciprocal have a product of 1.
To find the reciprocal of a fraction, exchange
the numerator and the denominator. Remember that
an integer can be written as a fraction with a
denominator of 1.
7
Multiplication and division are inverse
operations. They undo each other.
Notice that multiplying by the reciprocal gives
the same result as dividing.


8
Additional Example 1A Dividing Fractions
Divide. Write the answer in simplest form.
1 2
5 11
A.

Multiply by the reciprocal.
No common factors.
Simplest form
9
Additional Example 1B Dividing Fractions
Divide. Write the answer in simplest form.
3 8
B.
2
2

Write as an improper fraction.
Multiply by the reciprocal.
No common factors
19 16 1 R 3
10
Try This Example1A
Divide. Write the answer in simplest form.
7 15
3 4
A.

Multiply by the reciprocal.
No common factors.
Simplest form
11
Try This Example1B
Divide. Write the answer in simplest form.
2 5
3
4
B.

Write as an improper fraction.
Multiply by the reciprocal.
No common factors.
22 15 1 R 7
12
Additional Example 3B Evaluating Expressions
with Fractions and Decimals
Evaluate the expression for the given value of
the variable.
4 5
B.
k for k 5
5
13
Try This Example 3B
Evaluate the expression for the given value of
the variable.
4 7
B.
u , for u 9
Write as in improper fraction and multiply by the
reciprocal.
No common factors.
63 4 15 R 3
14
Additional Example 4 Problem Solving Application
The number of batches of cookies you can bake is
the number of batches using the oats that you
have. List the important information
15
Additional Example 4 Continued
Set up an equation.
16
Additional Example 4 Continued
Let n number of batches.
17
Additional Example 4 Continued
18
Try This Example 4
19
Try This Example 4 Continued
The number of complete trips the ship can make is
the number of trips that the ship can make with
the fuel on board. List the important information
20
Try This Example 4 Continued
Set up an equation.
Amount of fuel on board
Amount of fuel for one trip
Number of trips

21
Try This Example 4 Continued
Let t number of trips.
22
Try This Example 4 Continued