Correction :

19 - 12 = 7	26 - 18 = 8
2 × 9 = 18	31 - 19 = 12
3 + 5 = 8	11 × 6 = 66
12 + 2 = 14	1 × 6 = 6
8 : 4 = 2	24 : 6 = 4
4 : 2 = 2	5 - 5 = 0
4 × 10 = 40	11 + 21 = 32
32 - 24 = 8	8 × 10 = 80
23 + 22 = 45	17 + 15 = 32
6 + 9 = 15	27 - 24 = 3