Fraction Rules
Multiplying Fractions
Multiplying Mixed Numbers
Dividing Fractions
Dividing Mixed Numbers
100

How do we multiply fractions?

STRAIGHT ACROSS

100

2/3 * 4/5

8/15

100

1 1/2 * 5

15/2 or 7 1/2

100


2/5 -: 2/3

3/5

100

Convery this to an improper fraction and then flip:

2 1/12

12/25

200

How do we change a whole number into a fraction?

Put a 1 in the denominator, or put it over 1.

200

3/5 * 7/8

21/40

200

5/6 * 1 1/3

10/9 or 1 1/9

200

3/8 -: 2/3

9/16

200

2 1/8 -: 3

17/24

300

WHAT DO WE DO WHEN WE DIVIDE FRACTIONS?!?!?!

Keep - Change - Flip

300

4 * 7/8

7/2 or 3 1/2

300

3 1/3 * 1/4

5/6

300

6 -: 5/8

48/5 or 9 3/5

300

1 1/8 -: 1/10

45/4 or 11 1/4

400

The 2 ways to simplify fractions?!

1. Birthday cake and 

2. Cross simplify

400

5/12 * 9

15/4 or 3 3/4

400

1 1/3 * 2 1/8

17/6 or 2 5/6

400

1/2 -: 5/8

4/5

400

3 1/4 -: 1 1/2

13/6 or 2 1/6

500

Why would we cross simplify as opposed to simplifying at the end with the birthday cake?

If the numbers would be too large at the end, sometimes simplifying before you multiply makes it easier?

500

2/9 * 3/8

1/12

500

2 2/3 * 5 1/4

14

500

3/8 -: 7/12

9/14

500

3 1/2 -: 5 2/3

21/34

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