Correction :

23 + 14 = 37	14 + 12 = 26
16 - 2 = 14	21 + 1 = 22
20 + 0 = 20	5 - 1 = 4
23 + 4 = 27	4 + 1 = 5
15 + 22 = 37	7 + 19 = 26
15 + 7 = 22	11 + 14 = 25
22 - 22 = 0	24 + 13 = 37
6 + 11 = 17	20 + 3 = 23
33 - 14 = 19	1 × 7 = 7
12 : 2 = 6	6 - 2 = 4