Decimals
Decimals are expressed by a period or comma. For numbers larger than 999, don’t use a period or comma as a separator. A nonbreaking space (Option-Space bar) may be used instead.
International authority: Bureau International des Poids et Mesures (BIPM), https://www.bipm.org
Standard: BIPM SI Brochure
Rationale: Breaking up large numbers makes them easier to read, especially in tables. A nonbreaking space can’t be misinterpreted as a decimal marker.
Usage: Use a period to produce a decimal in English. Numbers may be divided in groups of three on either side of the decimal to make them easy to read. Use a nonbreaking space instead of a period or comma to divide numbers. Express large numbers in their smallest form to make them easier to read.
A kilobyte is 1024 bytes.
Apple sold 300 000 iMac computers in the first quarter.
Apple sold 3.7 million iMac computers in 2 years.