# Numbers, units and operators

Dr Henry Knipe and Dr Jeremy Jones et al.

Numbers, units and operators are used frequently in articles. We often quote the incidence of a condition as a range or say that x happens in more than y% of cases.

To try and keep the style similar across the site, and maximise the readability of these figures, we have some simple suggestions.

#### Numbers

In general:

• under 10: if a number is less than 10, use full text, e.g. four
• over 10: if a number is over 10, use digits, e.g. 5000
• thousands separators can be helpful for very big numbers and as a rule of thumb we advise to use a comma for numbers larger than 10,000, e.g. 10,700,000
• decimals: don't go crazy, more than 2 is usually a special case, e.g. 1.76
• fractions: no spaces either side of the slash, e.g. 1/4
##### Ranges

When ranges are included there should be no space either side of the dash, e.g. "22-27".  If the range is described within prose, there should be no dash, e.g. "the mean length is between 10 and 15 centimeters", not "the mean length is between 10-15 cm). Notice too, that the unit should be included in full if used in prose.

When giving a range, especially percentages, it is useful to pick a mean or median value that is representative of the range and then include the range in brackets after. Please see note on figures and percentages for further details and examples.

#### Units

When using units, there should always be a space between the number and unit. This stems from the fact that the number is a numeric representation of a word and that there is always a space between two words. If the number is written in text, the unit should be written in full:

• two millilitres
• 15 ml (remember that it is ml, not mls)

#### Operators

• where a percent sign is used, it should not have a preceding space, e.g. "22%"
• where an operator is used, it should not have a space after it, e.g. "<45"

URL of Article

## Article Information:

rID: 8386
Tag: help
Synonyms or Alternate Spellings:
• Numbers and operators
• Numbers
• Units
• Operators
• Numeric ranges
• Numeric range