Correction :

40 - 23 = 17	6 × 3 = 18
1 + 0 = 1	32 - 14 = 18
10 - 2 = 8	11 × 10 = 110
10 : 1 = 10	42 - 24 = 18
12 + 20 = 32	16 + 5 = 21
9 - 0 = 9	45 - 22 = 23
21 + 15 = 36	21 - 10 = 11
34 - 21 = 13	24 - 11 = 13
6 + 18 = 24	7 + 0 = 7
77 : 7 = 11	8 + 20 = 28