Vocabulary or Fraction rules
In a fraction problem, what is the top number called?
Numerator
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
What do you have to do when multiplying a whole number by a fraction?
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 -: 5/8
48/5 or 9 3/5
How do we convert a mixed number into an improper fraction?
Multiply the denominator with the whole number and add the numerator.
In a fraction, what is the bottom number called?
denominator
5/12 * 9
15/4 or 3 3/4
1 1/3 * 2 1/8
17/6 or 2 5/6
1/2 -: 5/8
4/5
What is the first rule in dividing fractions?
Keep fraction the same.
What should you do first to mixed numbers when multiplying or dividing fractions?
Convert, change, or make them to improper fractions.
2/9 * 3/8
1/12
2 2/3 * 5 1/4
14
3/8 -: 7/12
9/14
What fraction do we flip?
the second fraction