Correction :

44 - 24 = 20	17 + 13 = 30
1 + 22 = 23	40 - 17 = 23
15 + 1 = 16	17 + 19 = 36
3 + 7 = 10	12 + 7 = 19
7 + 5 = 12	90 : 9 = 10
6 + 20 = 26	9 + 0 = 9
8 + 10 = 18	10 × 3 = 30
4 - 1 = 3	23 - 4 = 19
2 × 9 = 18	55 : 5 = 11
13 + 23 = 36	1 × 9 = 9