Условие:

15 + 18 + 2;
45 + 5 + 26;
37 + 19 + 3;
56 + 20;
50 + 26;
56 + 6;
6032;
8032;
5032.

15 + 18 + 2 = 15 + (18 + 2) = 15 + 20 = 35
 
45 + 5 + 26 = 50 + 26 = 76
 
37 + 19 + 3 = (37 + 3) + 19 = 40 + 19 = 59
 
56 + 20 = (50 + 6) + 20 = (50 + 20) + 6 = 70 + 6 = 76
 
50 + 26 = 50 + (20 + 6) = (50 + 20) + 6 = 70 + 6 = 76
 
56 + 6 = 50 + (6 + 6) = 50 + 12 = 62
 
6032 = 60302 = 302 = 28
 
8032 = 80302 = 502 = 48
 
5032 = 50302 = 202 = 18