Adding Fractions with Unlike Denominators
1/4 + 2/3 =
11/12
4/5 - 1/3 =
7/15
1/2 and 3/5
LCD: 10
11 3/4 - 4 2/4 = ?
7 1/14
If the denominators are the same for two fractions, do we have to find the least common denominator (LCD)?
No, we can add or subtract the fractions as is.
4/9 + 1/6 =
11/18
4/3 - 2/7 =
22/21
5/12 and 2/9
LCD: 36
15 3/10 + 2 2/5 = ?
17 7/10
What is the first thing you do when you are adding or subtracting fractions with unlike denominators?
Find the multiples of the two denominators.
3/4 + 1/9 =
31/36
3/4 - 1/9 =
23/36
1/7 and 4/8
LCD: 56
7 2/7 - 4 3/14 = ?
3 1/14
How many wholes can we make from 16/4?
4
1/2 + 1/3 =
5/6
6/7 - 1/2 =
5/14
9/10 and 5/6
LCD: 30
100 - 27 5/8 = ?
72 3/8
What is the FRACTION left over after removing the wholes from 16/7?
2/7
1/4 + 3/7 =
19/28
9/10 - 1/4 =
13/20
1/4 and 2/3
LCD: 12
18 2/3 - 16 5/6 = ?
1 5/6
How can we express 5.6 as a mixed number (whole number and fraction?
5 and 6/10