Correction :

20 - 16 = 4	11 - 6 = 5
6 - 3 = 3	20 + 2 = 22
24 : 3 = 8	18 - 8 = 10
24 + 20 = 44	6 + 4 = 10
7 × 10 = 70	14 + 6 = 20
72 : 8 = 9	18 + 20 = 38
20 - 18 = 2	3 + 1 = 4
7 + 11 = 18	22 + 20 = 42
2 × 4 = 8	16 - 3 = 13
7 + 23 = 30	0 + 23 = 23