1 + 100 = 101
8 + 101 = 109
7 + 5 = 12
75 - 12 = 63
109 * 63 = 6867

100 * 8 = 800
1 + 5 = 6
75 + 7 = 82
800 + 82 = 882
6 + 882 = 888