Adding & Subtracting Decimals

Common Denominators

100

What is a common denominator for 2 & 3?

6, 12, 24.....

200

List a common denominator for 4 & 6 

12, 24, ......

300

Name a common denominator for 8 & 3

24, 48....

400

What is a common denominator for 6 & 8 

24, 48, ...

500

What is a common denominator for 10 & 20

10

Adding

100

2/4 + 3/4 

5/4 or 1 1/4

200

4/8 + 1/2

1

300

3/6 + 2/12

8/12 or 4/6

400

7/3 + 2/5

41/15

500

1 2/3 + 3 4/6

16/3 or 5 1/3

Subtracting

100

2/3-1/4

5/12

200

5/6 - 2/3

1/6

300

10/15-3/5

1/15

400

2 4/5- 1 1/10

17/10 or 1 7/10

500

5 3/4 - 1 2/3

49/12 or 4 1/12

Make it improper

100

Make 2 3/4 improper

11/4

200

Make 5 2/3 improper

17/3

300

Make 5 6/7 improper

41/7

400

Make 13 1/2 improper 

27/2

500

Make 2 8/9 improper 

26/9

LCD

100

What is the LCD for 10 & 5

5

200

What is the LCD for 8 & 3

24

300

What is the lowest common denominator for 3 & 9 

3

400

What is the LCD for 5 & 6 

30 

500

What is the LCD for 10 & 15 

30