Correction :

33 - 19 = 14	7 + 17 = 24
12 + 8 = 20	22 - 17 = 5
11 × 5 = 55	10 + 4 = 14
31 - 21 = 10	8 - 4 = 4
9 + 6 = 15	18 + 3 = 21
4 + 0 = 4	30 - 17 = 13
19 + 18 = 37	24 - 8 = 16
4 × 6 = 24	33 - 24 = 9
24 + 9 = 33	6 + 13 = 19
18 : 9 = 2	19 + 9 = 28