Условие:

40 + 7 + 3 + 18
50 + 26 + 8 + 2
30 + 9 + 6 + 1
80 − (35 − 20)
80 − (35 + 20)
80 + (35 − 20)

40 + 7 + 3 + 18 = 40 + (7 + 3) + (10 + 8) = 40 + 10 + 10 + 8 = 50 + 10 + 8 = 60 + 8 = 68
 
50 + 26 + 8 + 2 = 50 + (20 + 6) + (8 + 2) = 50 + 20 + 6 + 10 = 70 + 6 + 10 = 70 + 10 + 6 = 80 + 6 = 86
 
30 + 9 + 6 + 1 = 30 + (9 + 1) + 6 = 30 + 10 + 6 = 40 + 6 = 46
 
80 − (35 − 20) = 80 − (30 − 20 + 5) = 80 − (10 + 5) = 80 − 10 − 5 = 70 − 5 = 65
 
80 − (35 + 20) = 80 − (5 + 30 + 20) = 80 − (5 + 50) = 80 − 50 − 5 = 30 − 5 = 25
 
80 + (35 − 20) = 80 + (30 − 20 + 5) = 80 + (10 + 5) = 80 + 10 + 5 = 90 + 5 = 95