Correction :

18 - 9 = 9	10 × 8 = 80
25 - 1 = 24	5 + 24 = 29
8 + 5 = 13	0 + 6 = 6
13 + 17 = 30	11 + 18 = 29
5 + 18 = 23	10 × 7 = 70
47 - 23 = 24	1 + 5 = 6
4 × 4 = 16	43 - 19 = 24
36 - 20 = 16	9 × 3 = 27
80 : 10 = 8	10 × 6 = 60
19 - 15 = 4	25 - 4 = 21