Correction :

11 + 14 = 25	2 × 2 = 4
9 : 1 = 9	31 - 13 = 18
33 - 9 = 24	10 : 5 = 2
38 - 24 = 14	33 - 16 = 17
42 - 22 = 20	90 : 9 = 10
14 + 3 = 17	22 + 20 = 42
12 - 1 = 11	7 - 2 = 5
8 + 18 = 26	17 - 1 = 16
46 - 24 = 22	7 + 15 = 22
8 + 7 = 15	15 - 10 = 5