Correction :

22 + 13 = 35	9 - 5 = 4
24 - 18 = 6	6 + 12 = 18
24 - 13 = 11	8 + 12 = 20
22 + 9 = 31	6 : 6 = 1
6 - 5 = 1	16 - 16 = 0
16 + 15 = 31	12 + 21 = 33
40 - 16 = 24	19 - 8 = 11
13 + 0 = 13	22 - 20 = 2
23 - 16 = 7	7 × 6 = 42
24 - 10 = 14	6 × 1 = 6