Correction :

15 + 2 = 17	25 : 5 = 5
12 - 1 = 11	15 + 18 = 33
20 + 17 = 37	5 + 13 = 18
8 + 13 = 21	15 - 2 = 13
10 + 5 = 15	1 + 15 = 16
23 - 13 = 10	1 + 4 = 5
32 - 22 = 10	42 - 18 = 24
9 × 10 = 90	24 - 16 = 8
5 × 1 = 5	4 + 24 = 28
20 - 14 = 6	10 - 5 = 5