Fraction Rules
What needs to be the same when you add and subtract fractions?
The denominator
2/3 * 4/5
8/15
1 1/2 * 5
15/2 or 7 1/2
What is the reciprocal of
11/8
8/11
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
3/8 -: 2/3
9/16
Find the reciprocal of 14
1/14
To divide fractions we multiply by the what?
Reciprocal
4 * 7/8
7/2 or 3 1/2
4 1/2 -: 9
1/2
6 -: 5/8
48/5 or 9 3/5
Solve and simplify.
2/11 + 5/33
1/3
What should you always do to a fraction (your answer) if it is possible?
Simplify
2/9 * 3/8
1/12
Joe has 7 1/2 gallons of paint. He plans on using 1 1/2 gallons in each room. How many rooms is he able to paint?
5/1 or 5 rooms
1/2 -: 5/8
4/5
Solve and simplify.
(2/3 x 4) + 1/3
3/1 or 3
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.
It took Jason 2 5/6 hours to drive to the beach. It took Mary twice as long. How long did it take Mary to drive to the beach?
17/3 or 5 2/3
2 2/3 * 5 1/4
14
3/8 -: 7/12
9/14
Find the sum.
2 1/4 + 4 2/5
6 13/20