Equivalent fractions

Pizza

3/4

6/8 9/12

Multiply by 1

• 5 x 1 = 5

• 235 x 1 = 235

• 2/3 x 1 = 2/3

• a x 1 = a

What is 1?

12

2 1

5

5

1453

453 1

a

a

Raising Fractions

• Multiply numerator and denominator (top and bottom) of the fraction by the same number.

• This is the same thing as multiplying by 1.

15

6

3

3

5

2

Raising Fractions

• Raise 3/8 to 56ths. • Multiply numerator and denominator

(top and bottom) of the fraction by the same number.

568

3

Reducing Fractions• Opposite of raising.• Make the denominator smaller.• Divide numerator and denominator

by the same number.

21 7 356 7 8

Reducing Fractions

• Might take more than one step.• More than one way.• Divide numerator and denominator

by the same number.

40 2 20 2 10 2 556 2 28 2 14 2 7

Reducing Fractions

• Divide numerator and denominator by the same number.

4477

Why bother?

Tell your neighbor why you should reduce a fraction.

Practice

• Find a common denominator by raising the denominator:

• Reduce to lowest terms:

Comparing fractions

Does:

2 methods to compare fractions

1. Reduce/raise to a common denominator:

2. Cross multiply10 * 10 = 100 8 * 15 = 120

Which is greater?

With a new partner….

1. Put the fractions in order from least to greatest.

2. When you are done, compare your fractions to the table next to you.

Practice setPg. 230: Do at least 3 from problems #17-50

Pg. 231: Do at least 3 from problems # 51-62

Pg. 231: Choose any two from #63-70

Pg. 233: Do one of the sets of 4 (#93-96, 97-100 or 101-104)

When you are finished, please tell me the fraction of questions you answered correctly (for example 12/15 correct).

Multiplying fractions: pg. 1-24