Always use figures and symbols for percentages, measurements and currency.
- EXAMPLE: Question 12 is worth 10% of the available marks.
- EXAMPLE: The average height of a woman in the UK is 1.61m.
- EXAMPLE: The cost, at £5.99, was less than their overall budget of £50.
Note, that in British English per cent is two words. Use per cent where the number is also spelt out in words:
- EXAMPLE: twenty per cent.
With figures, use the per cent sign (%) preceded by a hard space
- EXAMPLE: 25 %
Always use figures with units of measurement that are denoted by symbols or abbreviations.
- EXAMPLE: EUR 50, 250 kW, 205 μg, 5 °C
The converse does not hold. If the units of measurement are spelt out, the numbers do not also have to be spelt out but may be written with figures:
- EXAMPLE: 250 kilowatts, 500 metres.
Write gram, kilogram AVOID: gramme, kilogramme
However, use tonne AVOID: ton (‘ton’ refers to the non-metric measure).
Write metre for the unit of length, meter for measuring instruments.
- EXAMPLE: the track was 6 metres
- EXAMPLE: you should check the electricity meter regularly
Insert hyphens when a fraction is used as an adverb or adjective
- EXAMPLE: two-thirds complete, a two-thirds increase
Do not insert hyphens when the fraction is used as a noun
- EXAMPLE: an increase of two thirds
Avoid combining figures and words:
- EXAMPLE: two-thirds completed AVOID: 2/3 completed
When using figures for a fraction, use the fraction symbol where possible and close it up to any previous figure
- EXAMPLE: 11⁄2 years.
When a range is written out, repeat symbols and multiples (ie. thousand, million, etc.):
- EXAMPLE: from EUR 20 million to EUR 30 million between 10 °C and 70 °C
When a range is indicated by a hyphen, do not repeat the symbol or multiple if they do not change and close up the hyphen between the figures:
- EXAMPLE: €20-30 million, 10-70 °C
If the symbol or multiple changes, however, leave a blank space on either side of the hyphen:
- EXAMPLE: 100 kW - 40 MW
Language Boutique 'Writing Numbers – Periods or Commas?' Retrieved from https://language-boutique.com/lost-in-translation-full-reader/writing-numbers-points-or-commas.html