15 1/2 - 2 3/8 - 5 5/6 - 6 3/4 + 10 2/3 - 5 5/8= 15 1/2 - 5 5/6 - (2 3/8 + 5 5/8) - 6 

3/4 + 10 2/3 = (15 - 5) + (1/2 - 5/6) - 8 + (10-6) + (2/3 - 3/4) =

10 + (3/6 - 5/6) - 8 +4 + (8/12 - 9/12) = 6 - 2/6 - 1/12 = 

6 - 4/12 - 1/12 = 5 + (12/12- 5/12) = 5 7/12