Correction :

16 + 14 = 30	22 - 20 = 2
8 : 8 = 1	42 : 6 = 7
10 + 1 = 11	10 - 3 = 7
19 + 0 = 19	13 + 18 = 31
12 - 0 = 12	31 - 9 = 22
39 - 19 = 20	39 - 24 = 15
12 - 9 = 3	2 + 19 = 21
19 - 2 = 17	4 - 3 = 1
13 + 13 = 26	35 - 13 = 22
7 - 4 = 3	13 + 17 = 30