Correction :

15 : 5 = 3	6 × 7 = 42
35 - 14 = 21	24 + 16 = 40
23 + 7 = 30	10 - 7 = 3
4 - 1 = 3	4 × 4 = 16
6 × 10 = 60	11 + 13 = 24
23 + 16 = 39	40 - 18 = 22
17 + 11 = 28	10 × 5 = 50
21 + 10 = 31	6 + 6 = 12
10 - 5 = 5	11 × 2 = 22
11 - 8 = 3	38 - 18 = 20