19.1.1 Numbers of 4 or More Digits to Either Side of the Decimal Point.

Commas are not used in large numbers. In 4-digit numbers, the digits are set closed up. For numbers of 10 000 or greater, a half-space or thin space is used to separate every 3 digits starting from the right-most integer (or, in numbers with decimals, from the left of the decimal point). For numbers with 5 or more digits to the right of the decimal point, a half-space is used between every 3 digits starting from the right of the decimal point (see also , Units of Measure, Use of Numerals With Units).The exact weight of the salt was 8.453 98 g, ...Less