Correction :

21 - 3 = 18	5 + 22 = 27
11 + 6 = 17	27 - 23 = 4
9 + 16 = 25	5 × 7 = 35
20 + 8 = 28	15 + 24 = 39
33 - 21 = 12	15 - 11 = 4
15 - 6 = 9	24 - 9 = 15
32 : 4 = 8	16 : 8 = 2
11 + 14 = 25	8 - 1 = 7
17 - 14 = 3	15 - 0 = 15
22 - 12 = 10	22 + 18 = 40