Fraction Rules
What is a strategy to simplify fractions? What do we use?
Use multiplication facts or divide by least common factor.
2/3 * 4/5
8/15
1 1/2 * 5
15/2 or 7 1/2
I have five cookies and I want to share them with me and my three friends. How much of the cookies do I get?
1 1/4
Multiply straight across (multiply numerators and multiply denominators)
How do we change a whole number into a fraction?
Put a 1 in the denominator, or put it over 1.
3/5 * 7/8
21/40
5/6 * 1 1/3
10/9 or 1 1/9
1/8 -: 3
1/24
A dog food bowl holds 3 cups of food. Each scoop of food is 1/4 cups. How many scoops will it take to fill the bowl?
12 scoops
3 word phrase to help us with dividing fractions.
Keep - Change - Flip
4 * 7/8
7/2 or 3 1/2
3 1/3 * 1/4
5/6
6 -: 1/8
48
How do we convert a mixed number into a fraction?
Multiply the denominator with the whole number and add the numerator.
When dividing fractions, you are changing into ______________________ fractions?
multiplying
5/12 * 9
15/4 or 3 3/4
1 1/3 * 2 1/8
17/6 or 2 5/6
1/2 -: 5
1/10
Velma bought 1/4 of a pound of butter. She split the butter into 8 equal pieces. How much did each piece weigh?
1/32 of a pound
What should you do first to mixed numbers when multiplying or dividing fractions?
Convert them to improper fractions.
Change them to improper fractions.
Make them improper fractionns.
2/9 * 3/8
1/12
2 2/3 * 5 1/4
14
1/12 -: 3
1/36
What fraction do we flip?
the second fraction