1. 2 2/5 - (1/4 + 7/10) = 2 2/5 - (5/20 + 9/20) = 2 2/5 - 19/20 = 1 9/20
2. 9 - (1 5/8 + 3/20) = 9 - (1 25/40 + 6/40) = 9 - 1 31/40 = 7 9/40
3. 3 - (1/6 + 2/3) = 3 - (1/6 + 4/6) = 3 - 5/6 = 2 6/6 - 5/6 = 2 1/6
4. 4 5/6 - (2 3/8 + 7/12) = 4 5/6 - 2 23/24 = 45/24 = 15/8 = 1 7/8
5. 7 - (2 3/4 + 7/12) = 7- 3 1/3 = 6 3/3 - 3 1/3 = 3 2/3
6. 6 1/4 - (3 2/5 + 3/8) = 6 1/6 - (3 16/40 + 15/40) = 6 1/6 - 3 31/40 = 2 19/40