Correction :

42 : 7 = 6	5 × 11 = 55
12 + 12 = 24	29 - 5 = 24
41 - 20 = 21	0 + 7 = 7
20 + 16 = 36	19 - 1 = 18
39 - 21 = 18	29 - 17 = 12
14 - 6 = 8	21 - 16 = 5
17 + 13 = 30	12 - 12 = 0
5 + 3 = 8	28 - 8 = 20
24 - 21 = 3	10 : 5 = 2
8 - 1 = 7	7 - 0 = 7