Correction :

15 - 13 = 2	23 + 23 = 46
28 - 14 = 14	21 - 3 = 18
41 - 24 = 17	10 - 0 = 10
20 - 6 = 14	15 + 11 = 26
16 - 7 = 9	23 - 11 = 12
33 - 13 = 20	2 + 10 = 12
28 - 11 = 17	24 - 20 = 4
25 - 7 = 18	12 + 23 = 35
3 × 11 = 33	23 + 0 = 23
5 + 20 = 25	11 + 14 = 25