calcolatrice / kal'kulyator
30 mm + 18 mm + 24 mm = 72 mm
45 + (45 - 21) = 45 + 45 - 21 = 90 - 21 = 69
calcolatrice / kal'kulyator
4 * 2 → 8 4 * 3 → 12 ...
8 / 4 → 2 12 / 4 = 3 ...
5 * 2 → 10 5 * 3 → 15 ...
10 / 5 → 2 15 / 5 → 3 ...

75 * 3 → 225
225 - 162 → 63
128 + 162 = 290
290 / 5 → 58