ADDING AND SUBTRACTING FRACTIONS WITH UNLIKE DENOMINATORS

Adding

100

1/2 + 2/5

What is 9/10

200

6/10 + 2/4

1  2/20

300

5/18 + 2/3

17/18

400

3/5 + 5/6

1  13/30

500

10/12 + 8/9

1 26/36

Subtracting

100

5/6 - 1/3

3/6

200

7/8 - 5/6

1/24

300

4/8 - 1/12

20/48

400

3/13 - 7/39

2/39

500

9/11 - 2/3

5/33

Adding with mixed numbers

100

1 1/2 + 1 2/3

3 1/6

200

5 7/8 + 3 4/6

9  13/24

300

10 9/15 + 6 5/30

16  23/30

400

15 6/9 + 7 5/6

23   9/18

500

21 5/20 + 15 3/80

36 23/80

Subtracting with mixed numbers

100

1 2/3 - 1 1/5

7/15

200

4 5/6 - 2 3/5

2  7/30

300

5  1/8 - 2  3/4

2  1/8

400

10 - 4/6

9  2/6

500

14 3/8- 2 9/10

11  19/40

Mystery

100

21 - 9/10

20 1/10

200

5 2/3 + 2 5/6

8 3/6

300

5/6 + 7/8

1 17/24

400

10 15/30 - 8 10/90

2 35/90

500

4  5/6 - 3  8/9

17/18