Correction :

4 + 8 = 12	43 - 20 = 23
14 + 20 = 34	46 - 24 = 22
19 + 19 = 38	14 - 10 = 4
20 : 5 = 4	27 - 10 = 17
5 × 4 = 20	20 + 8 = 28
30 - 9 = 21	14 + 9 = 23
4 + 10 = 14	38 - 15 = 23
70 : 10 = 7	6 + 1 = 7
18 - 17 = 1	5 × 3 = 15
38 - 20 = 18	3 : 1 = 3