1/12 + 5/6 = 1/12 + 10/12 = 11/12
11/12 - 2/8 = 11/12 - 1/4 = 8/12 = 2/3
1 - 4/7 = 7/7 - 4/7 = 3/7
6/27 + 1/18 = 2/9 + 1/18 = 4/18 + 1/18 = 5/18
1/12 + 5/6 = 1/12 + 10/12 = 11/12
11/12 - 2/8 = 11/12 - 1/4 = 8/12 = 2/3
1 - 4/7 = 7/7 - 4/7 = 3/7
6/27 + 1/18 = 2/9 + 1/18 = 4/18 + 1/18 = 5/18