Correction :

16 + 5 = 21	8 + 12 = 20
9 + 3 = 12	22 - 8 = 14
5 + 24 = 29	10 - 2 = 8
6 - 4 = 2	13 - 6 = 7
19 - 15 = 4	37 - 17 = 20
7 + 1 = 8	6 × 9 = 54
22 + 6 = 28	28 - 14 = 14
5 : 1 = 5	20 - 3 = 17
20 + 19 = 39	9 - 3 = 6
22 - 0 = 22	36 - 19 = 17