1. 3 1/3 + 1 1/4 ,
2. 4 3/4 -2 1/2
3. 2 3/10 + 2/5
4. 3 5/8 - 1 1/4
5. 2 1/5 + 2 3/10
6 . 3 3/8 + 2 1/2