Correction :

22 + 5 = 27	14 + 23 = 37
9 + 16 = 25	12 + 8 = 20
39 - 22 = 17	18 - 9 = 9
15 - 15 = 0	2 + 6 = 8
16 - 7 = 9	24 - 2 = 22
12 + 0 = 12	29 - 19 = 10
26 - 4 = 22	7 : 7 = 1
22 + 20 = 42	16 + 4 = 20
42 - 19 = 23	23 - 16 = 7
28 - 10 = 18	14 - 3 = 11