Correction :

18 + 15 = 33	5 + 9 = 14
3 - 0 = 3	11 × 7 = 77
22 + 11 = 33	5 + 21 = 26
8 + 11 = 19	20 - 5 = 15
23 - 23 = 0	43 - 24 = 19
29 - 15 = 14	17 + 15 = 32
8 + 15 = 23	5 + 8 = 13
17 - 6 = 11	14 - 3 = 11
41 - 18 = 23	5 × 11 = 55
9 : 1 = 9	4 - 0 = 4