6 1/7 - 1 = 5 1/7;
5 - 2 1/2 = 3 1/2
5 7/9 - 3 = 2 7/9
4 - 2 3/5 = 1 2/5
6 3/4 - 2 1/4 = 4 1/2
1 5/9 - 8/9 = 2/3
4 7/8 - 2 1/8 = 2 5/8
1 2/7 - 3/8 = 51/56
3 5/6 - 1 1/6 = 2 2/3
6 1/7 - 1 = 5 1/7;
5 - 2 1/2 = 3 1/2
5 7/9 - 3 = 2 7/9
4 - 2 3/5 = 1 2/5
6 3/4 - 2 1/4 = 4 1/2
1 5/9 - 8/9 = 2/3
4 7/8 - 2 1/8 = 2 5/8
1 2/7 - 3/8 = 51/56
3 5/6 - 1 1/6 = 2 2/3