same denominators
TIBO
mixed number
multiply decimals
+ -
100
2/3  - 1/3 

1/3

100

12/4

3

100

3  1/2

7/2

100

12.3 x 4

49.2

100

2.3 + 4

6.3

200

7/8 + 1/8 

8/8 or 1

200

21/4

5  1/4

200

4  1/8

33/8

200

13.32 x 2

26.64

200

74.5 + 2.32

76.82

300

1/7 + 4/7 

5/7

300

13/4

3  1/4

300

5  1/7

36/7

300

41.2 x 2

164.8

300

12 + 6.3

18.3

400

1/4 + 2/4 

3/4

400

19/ 2 

9  1/2

400

9  4/5

49/5

400

54.6 x 7

382.2

400

20.3 + 3

23.3

500

11/13 - 8/13

3/13

500

10 / 4

2 2/4

500

8  6/7

62/7

500

23.6  x 5

118

500

12.3 + 6.17

18.47