Correction :

11 - 3 = 8	31 - 21 = 10
21 + 3 = 24	80 : 8 = 10
6 + 22 = 28	21 - 17 = 4
23 + 21 = 44	19 - 0 = 19
10 : 5 = 2	16 + 5 = 21
9 : 9 = 1	45 : 5 = 9
9 - 3 = 6	3 + 14 = 17
16 - 15 = 1	26 - 16 = 10
11 × 1 = 11	4 + 7 = 11
24 : 8 = 3	11 : 11 = 1