## Thursday, March 25, 2010

### Brayden's Fraction Growing Post

This video shows how I got the answers to my Fraction Quiz.

Now I'm going to explain two ways to multiply a fraction by a whole number.

One way would be drawing 4 groups of 1/2

Another way would be to multiply the two numerators.

Now I'm going to explain how to divide a fraction by a whole number.

My example is 1/4 ÷ 2.

Use your fraction strip and divide it into fourths. Then color in 1/4 of it. Next you divide your fraction strip in half as seen in the picture.

Next we have to answer a word problem.

12) It takes 4/5 of a roll of ribbon to wrap six packages. What fraction of a roll does it take to wrap three packages?

It would take 2/5 of a roll to wrap three packages.

I found that out because if 4/5 of a roll of ribbon wraps six packages you can just divide 4/5 by 2 and get 2/5 which would wrap three packages.

COMMENT!

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Part 2

Fraction x Fraction

Fraction x mixed number

4/5 x 1 1/2

First you have to convert the mixed number to a improper fraction.

1 x 2 = 2
2 + 1 = 3
= 3/2

Then you multiply the two fractions.

4/5 x 3/2 = 12/10 or 6/5 or 1 1/5

Mixed number x Mixed number

2 1/3 x 2 2/3

First you convert the mixed numbers to improper fractions.

2 x 3 = 6
6 + 1 = 7
= 7/6

2 x 3 = 6
6 + 2 = 8
= 8/7

Then you multiply the two improper fractions .

7/6 x 8/7 = 56/42 or 4/3 or 1 1/3

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Part 3

Division

When you're dividing fractions you multiply the numerators by the denominator in the other fraction.

ex.

3/4 divided 1/2

You multiply 3 x 2 and 1 x 4 = 6/4

Then you make it a mixed fraction.

6/4 = 1 1/2

1 1/2 divided by 3/4

First you have to convert the mixed number to a improper fraction.

3/2 x 3/4

3 x 4 = 12

3 x 2 = 6

= 12/6

or 2