Name
Reteaching
8-4
Multiplying Mixed Numbers
How to find the product of two mixed numbers: Find 3_23 ! 4_12.
Step 1
Estimate the product by rounding.
Step 2
Round 3_23 to 4 and 4_12 to 5:
4 ! 5 " 20
Write each mixed number as an improper
fraction.
9
11 and 4_
1 "_
3_23 " __
3
2
2
Look for common factors and simplify.
9
3
11 × _
11 × _
/ " __
3_23 ! 4_12 " __
3/
2
1
2
3
1
Step 3
Multiply the numerators and denominators.
Write the product as a mixed number.
3 " __
33
11 ! _
__
1
2
2
33 " 16_
1
__
2
2
Find each product. Simplify if possible.
1. 2_34 ! 3_12
2. 2_15 ! 2_23
3. 6 ! 3_14
4. 1_25 ! 3_14
5. 4_12 ! 16
6. 1_38 ! 2_12
Evaluate each expression for K " 2_13 .
7. 12K
8. 1_34 K
9. 2_23 K
10. Reasonableness What is a reasonable estimate for 7_34 ! 2_23 ?
Explain.
11. The cups of mushrooms in a recipe is 2_12 times the cups of onions.
The cups of onions is 1_12 . Solve c " 1_12 ! 2_12 to find c, the cups of
mushrooms.
© Pearson Education, Inc. 6
Reteaching 8-4
16_12 is close to 20, so the answer is reasonable.
36
Topic 8
Name
Reteaching
8-4
Multiplying Mixed Numbers
How to find the product of two mixed numbers: Find 3_23 ! 4_12.
Step 1
Round 3_23 to 4 and 4_12 to 5:
4 ! 5 " 20
Estimate the product by rounding.
Step 2
Write each mixed number as an improper
fraction.
9
11 and 4_
1 "_
3_23 " __
3
2
2
Look for common factors and simplify.
9
3
11 × _
11 × _
/ " __
3_23 ! 4_12 " __
3/
2
1
2
3
1
Step 3
3 " __
33
11 ! _
__
1
2
2
33 " 16_
1
__
Multiply the numerators and denominators.
Write the product as a mixed number.
2
2
Find each product. Simplify if possible.
1. 2_34 ! 3_12
4. 1_25 ! 3_14
9_58
11
4__
20
2. 2_15 ! 2_23
5. 4_12 ! 16
Evaluate each expression for K " 2_13 .
7. 12K
28
8. 1_34 K
13
5__
15
72
1
4__
12
6. 1_38 ! 2_12
19_12
7
3__
16
9. 2_23 K
6_29
3. 6 ! 3_14
10. Reasonableness What is a reasonable estimate for 7_34 ! 2_23 ?
_
3
Explain.
24, since 74 rounds to 8 and
2_23 rounds to 3 and 8 ! 3 " 24.
11. The cups of mushrooms in a recipe is 2_12 times the cups of onions.
The cups of onions is 1_12 . Solve c " 1_12 ! 2_12 to find c, the cups of
mushrooms.
3_34 c of mushrooms
© Pearson Education, Inc. 6
Reteaching 8-4
16_12 is close to 20, so the answer is reasonable.
36
Topic 8