a. 6/7 + 9 5/7
6/7 ≈ 1
9 5/7 ≈ 10
6/7 + 9 5/7 ≈ 1 + 10 = 11
b. 3 8/10 + 9 3/4
3 8/10 ≈ 4
9 3/4 ≈ 10
3 8/10 + 9 3/4 ≈ 4 + 10 = 14
c. 5 - 2 5/7
5 = 5
2 5/7 ≈ 3
5 - 2 5/7 ≈ 5 - 3 = 2
d. 3 4/5 - 2 3/4
3 4/5 ≈ 4
2 3/4 ≈ 3
3 4/5 - 2 3/4 ≈ 4 - 3 = 1
e. 11 9/11 - 5 6/11
11 9/11 ≈ 12
5 6/11 ≈ 6