Correction :

6 - 6 = 0	16 + 1 = 17
3 + 11 = 14	18 + 3 = 21
23 + 9 = 32	13 - 11 = 2
15 - 7 = 8	77 : 11 = 7
5 + 5 = 10	13 - 5 = 8
17 - 17 = 0	48 : 6 = 8
2 - 1 = 1	2 + 21 = 23
5 + 20 = 25	10 × 11 = 110
19 + 3 = 22	41 - 17 = 24
22 + 20 = 42	18 - 10 = 8