Correction :

3 + 8 = 11	7 + 6 = 13
2 + 10 = 12	34 - 18 = 16
2 × 8 = 16	21 - 5 = 16
7 + 17 = 24	12 + 9 = 21
13 - 5 = 8	3 + 6 = 9
8 : 2 = 4	42 : 7 = 6
17 + 24 = 41	41 - 18 = 23
24 - 1 = 23	5 - 2 = 3
27 - 15 = 12	45 : 5 = 9
0 + 7 = 7	11 + 6 = 17