Correction :

44 - 24 = 20	12 + 8 = 20
25 - 16 = 9	3 × 3 = 9
16 - 5 = 11	21 + 19 = 40
10 + 24 = 34	5 × 1 = 5
16 + 18 = 34	5 + 6 = 11
15 + 18 = 33	23 + 0 = 23
0 + 23 = 23	3 × 10 = 30
6 + 2 = 8	15 - 9 = 6
22 - 2 = 20	13 + 18 = 31
28 - 9 = 19	20 - 19 = 1