Correction :

0 - 0 = 0	28 - 7 = 21
5 + 8 = 13	13 + 21 = 34
33 - 10 = 23	19 - 17 = 2
5 × 11 = 55	12 - 10 = 2
8 + 18 = 26	30 - 11 = 19
50 : 5 = 10	12 - 3 = 9
17 - 11 = 6	16 + 10 = 26
6 + 19 = 25	32 - 16 = 16
5 × 3 = 15	6 × 6 = 36
8 × 9 = 72	24 + 15 = 39