5/9
4/7 + 1/7
9/10 - 2/10
1/9 + 2/9
1 - 2/4
3/4
1
3/7
3/9 + 2/9
2/4 + 1/4
5/7
4/10 - 1/10
8/9 - 1/9
7/9
5/7 - 2/7
3/9
1/2 + 1/2
2/4
7/10
3/10