Numerals and mathematical conventions

Decimals

In Italian, as a rule, the punto (point) separates thousands, the vìrgola (comma) decimals, e.g. 1.000.000 = un milione; 23,42 = ventitré virgola quarantadue/ventitré e quarantadue (centesimi). note that the English reading twenty-three point four two has no direct equivalent in Italian (ventitré virgola quattro due is not used). However, it should be pointed out that the use of the decimal point, if not practiced, is certainly widely understood in Italy, especially in the scientific world.

For the sake of clarity, the Anglo-American conventions (i.e. decimal point) have been applied throughout this text, even in Italian contexts.

Mathematical operations

When doing operations, the following Italian expressions are worthy of notice:

• in sums (addizioni), in everyday casual speech “plus” can be simply e, and “equals” is omitted, e.g. 2 + 3 = 5 due e tre cinque (R1–2), rather than due più tre è uguale a (R2–3)/fa cinque. Cf. the idiom in quattro e quattr'otto (“in the twinkling of an eye”).

• in divisions (divisioni), “divided by” becomes diviso, e.g. 8 : 2 = 4 otto diviso due è uguale a (R2–3)/fa quattro

• in ratios (proporzioni), English “is to” becomes Italian sta a, e.g. 4 : 6 = 6 : 9 quattro sta a sei come sei sta a nove

• in raising to a power (elevazione a potenza), “squared” is translated al quadrato, “cubed” al cubo, and, generally, “to the nth power” becomes all'ennesima (potenza), e.g. 33tre al cubo/alla terza (potenza)