Correction :

10 - 9 = 1	4 + 19 = 23
11 - 9 = 2	45 - 23 = 22
5 × 6 = 30	24 + 23 = 47
20 - 9 = 11	4 - 3 = 1
3 × 2 = 6	60 : 10 = 6
21 - 11 = 10	12 - 12 = 0
20 + 12 = 32	1 + 14 = 15
5 - 4 = 1	24 + 0 = 24
22 + 17 = 39	5 + 4 = 9
25 - 20 = 5	36 - 19 = 17