This post is part of the Canadian Style series.
5.24 Comparative and inclusive numbers
(c) Opinions differ on the proper forms for inclusive numbers written as numerals. To ensure clarity, abbreviate second numbers according to the following principles.
- Repeat all digits in numbers below 100 (e.g. 62–98).
- Repeat all digits where the first number is 100 or a multiple of 100 (e.g. 200–236).
- Where the first number is in the range 101–109, in multiples of 100, use the changed part only and omit unnecessary zeros (e.g. 502–9).
- Where the first number is in the range 110–199, in multiples of 100, use two or more digits, as needed (e.g. 1973–91).
- With numbers of four digits, use all digits if three of the change (e.g 1492–1973).
Note: repeat all digits if the second number is an even hundred (e.g. 697–700) and if they are years BC.