Correction :

8 - 5 = 3	27 - 10 = 17
18 - 10 = 8	7 : 7 = 1
8 - 0 = 8	6 : 2 = 3
45 - 21 = 24	22 - 10 = 12
40 - 19 = 21	4 + 5 = 9
23 - 22 = 1	22 + 9 = 31
31 - 12 = 19	27 - 12 = 15
6 : 6 = 1	9 - 9 = 0
5 - 2 = 3	27 - 4 = 23
4 + 9 = 13	11 × 3 = 33