Correction :

13 + 23 = 36	36 - 19 = 17
11 : 1 = 11	19 - 18 = 1
20 + 9 = 29	3 × 9 = 27
11 + 0 = 11	110 : 10 = 11
14 : 2 = 7	32 - 8 = 24
23 - 9 = 14	24 + 11 = 35
1 + 17 = 18	5 - 4 = 1
23 + 19 = 42	1 + 20 = 21
30 - 10 = 20	6 × 1 = 6
8 - 6 = 2	10 × 6 = 60