Correction :

23 + 0 = 23	22 - 4 = 18
22 : 11 = 2	33 - 24 = 9
12 + 19 = 31	1 × 2 = 2
42 - 18 = 24	2 × 2 = 4
88 : 8 = 11	21 - 1 = 20
2 + 17 = 19	6 - 0 = 6
2 + 19 = 21	11 + 21 = 32
7 × 9 = 63	15 + 17 = 32
1 × 11 = 11	13 + 8 = 21
19 - 18 = 1	11 + 12 = 23