1. Practice 1 Group with subtraction this way.
1 x 7 = 7
9 - 1 = 8
1 x 5 = 5
4 x 1 = 4
6 - 1 = 5
1 x 3 = 3
6 x 1 = 6
1 x 9 = 9
2 x 1 = 2
4 - 1 = 3
8 x 1 = 8
1 x 4 = 4
8 - 1 = 7
9 x 1 = 9
1 x 1= 1
3 - 1 = 2
1 x 6 = 6
5 - 1 = 4
7 - 1 = 6
7 x 1 = 7
5 x 1 = 5
1 x 8 = 8
2 - 1 = 2
3 x 1 = 3