Answer :

TSO
5 1/9 rounds to 5
1 7/8 rounds to 2

5+2 = 7

11/20 rounds to 1
5/8 rounds to 1

1-1 = 0

8/9 rounds to 1
2 13/15 rounds to 3

1+3 = 4
5 1 / 9 + 1 7 / 8 = 6 + 1 / 9 + 7 / 8 = 6 + 8 / 72 + 63 / 72 = 6 + 71 / 72 ≈ 6,.98 round to tens( + 1 decimal place )  7 ;

11 / 20 - 5 / 8 = 22 / 40 - 25 / 40 = -3 / 40 ≈ -0. 075 round to tens( + 1 decimal place )  - 0.1 ;

8 / 9 + 2 13 / 15 = 2 + 8 / 9 + 13 / 15 = 2 + 40 / 45 + 39 / 45 = 2 + 79 / 45 ≈ 3.75
 round to tens( + 1 decimal place ) 3.8 ;