Adding Fractions with Unlike Denominators
1/4 + 2/3 =
11/12
4/5 - 1/3 =
7/15
1/2 and 3/5
LCD: 10
What does it mean to be "equivalent"?
To be equal to or the same as.
List the factors of 9
1, 3, 9
4/9 + 1/6 =
*write your answer in simplest form
11/18
4/3 - 2/7 =
22/21
5/12 and 2/9
LCD: 36
A number that you multiply by to get a product
List the factors of 18
1, 2, 3, 6, 9, 18
3/4 + 1/9 =
31/36
3/4 - 1/9 =
23/36
1/7 and 4/8
LCD: 56
What is the "lowest (or least) common multiple"?
The smallest common multiple of two or more numbers
List the factors of 21
1, 3, 7, 21
1/2 + 1/3 =
5/6
6/7 - 1/2 =
5/14
9/10 and 5/6
LCD: 30
How is the lowest ("least") common multiple useful in adding and subtraction fractions?
**BEST EXPLANATION**
List the factors of 30
1, 2, 3, 5, 6, 10, 15, 30
1/4 + 3/7 =
19/28
9/10 - 1/4 =
*Write your answer in simplest form
13/20
1/4 and 2/3
LCD: 12
What is the last step in the process of adding and subtracting fractions?
Change your denominators to common denomintors and then add/subtract.
List the factors of 36
1, 2, 3, 4, 6, 9, 18, 36