Correction :

35 - 13 = 22	20 + 9 = 29
35 : 5 = 7	12 + 1 = 13
34 - 13 = 21	30 - 24 = 6
22 + 23 = 45	3 + 15 = 18
12 - 11 = 1	21 - 12 = 9
18 - 4 = 14	16 - 9 = 7
8 + 12 = 20	18 + 2 = 20
21 - 19 = 2	44 - 24 = 20
22 + 17 = 39	19 - 4 = 15
21 : 3 = 7	20 + 8 = 28