Correction :

19 - 16 = 3	18 + 15 = 33
31 - 13 = 18	8 × 1 = 8
6 - 3 = 3	3 + 16 = 19
29 - 11 = 18	3 + 13 = 16
18 - 10 = 8	4 + 1 = 5
19 - 15 = 4	1 + 22 = 23
15 - 5 = 10	21 - 1 = 20
38 - 22 = 16	9 + 12 = 21
24 + 24 = 48	21 + 0 = 21
16 - 14 = 2	19 + 8 = 27