Correction :

88 : 11 = 8	18 + 15 = 33
6 - 5 = 1	17 + 5 = 22
19 - 14 = 5	24 + 8 = 32
50 : 5 = 10	11 + 7 = 18
15 + 15 = 30	3 + 12 = 15
40 : 10 = 4	31 - 14 = 17
40 - 17 = 23	13 + 12 = 25
36 - 23 = 13	8 + 12 = 20
4 + 21 = 25	23 - 8 = 15
20 + 13 = 33	27 - 5 = 22