To multiply fractions: 1. Multiply the numerators together. 2. Multiply the denominators together. 3. Simplify if possible. To divide fractions: 1. Invert the second fraction. 2. Multiply the first fraction by the inverted second fraction. 3. Simplify if possible.

1. Fraction
Multiplication
And Cancelation

2. Fraction Multiplication
• Here are some fraction
multiplication problems 4 1 4
• Can you tell how to
multiply fraction from
5 7 35
these examples?
2 5 10 2 5 10
3 1 3
3 7 21
3 5 15
1 1 1
4 12 48
3 3 9
6 4 24
5 10 50

3. Multiplication
• Multiply numerator by numerator
• And denominator by denominator
2 5 10
3 1 3
N1 N2 N1 N 2
D1 D2 D1 D2

4. Try some.
• Multiply the following:
1 5 5 5
3 8 8 8
2 4 4 2
3 5 9 3

5. Answers
• Multiply the following:
1 5 5 5 5 25
3 8 24 8 8 64
2 4 8 4 2 8
3 5 15 9 3 27

6. Fraction Division
Opposite of Multiplication

7. The opposite number:
• Invert
• Called the reciprocal
• 3 4
invert to make
4 3

8. To Divide
• Invert the
second number
• Multiply
2 3 2 4 8
5 4 5 3 15

9. 1
2
4
•
1 2
4 1
1 1
4 2
1 1 1
4 2 8

10. 3 1
2
4 5
•
3 11
4 5
3 5
4 11
3 5 15
4 11 44