Correction :

11 + 13 = 24	2 + 24 = 26
9 × 4 = 36	28 - 16 = 12
9 + 4 = 13	50 : 10 = 5
39 - 16 = 23	7 + 16 = 23
6 × 1 = 6	11 × 8 = 88
9 + 9 = 18	44 - 21 = 23
19 + 4 = 23	4 × 1 = 4
7 + 24 = 31	18 - 16 = 2
44 - 22 = 22	5 + 19 = 24
25 : 5 = 5	24 - 3 = 21