3 5/8 - 2 7/16 = ( 3 - 2 ) + 5/8 - 7/16 = 1 + 10/16 - 7/16 = 1 3/16
4 7/10 - 9 8/15 = ( 4 - 9 ) + 7/10 - 8/15 = -5 + 21/30 - 16/15 = -5 1/3
6 3/10 - 5 11/12 = ( 6 - 5 ) + 3/10 - 11/12 = 1 + 18/60 - 55/60 = 23/60
5 1/3 - 9 7/9 = ( 5 - 9 ) + 1/3 - 7/9 = -4 + 3/9 - 7/9 = -4 4/9