1:8 × 10 - 8 × 7
2:(8 × 10) - 8 × 7
3:8 × 10 -(8 × 7)
4:(8 × 10) - (8 × 7)
5:8 × 10 - 7 × 8
6:(8 × 10) - 7 × 8
7:8 × 10 -(7 × 8)
8:(8 × 10) - (7 × 8)
9:10 × 8 - 8 × 7
10:(10 × 8) - 8 × 7
11:10 × 8 -(8 × 7)
12:(10 × 8) - (8 × 7)
13:10 × 8 - 7 × 8
14:(10 × 8) - 7 × 8
15:10 × 8 -(7 × 8)
16:(10 × 8) - (7 × 8)