Numbers, measurement and currencies


1–9—write out one, nine, (i.e. single-digit numbers); from then on the number 10, 11 etc.

If a mix of related numbers above and below nine appears in one sentence, use figures:

  • Unbelievably, only 2 of the 110 people on the train were injured.

Always start a sentence with a word:

  • Two out of 110 people were injured.


For dollars, you can use just the $ symbol if it’s clear that it represents the local currency, but identify all other types of dollar (e.g. CAN$). When using the code and symbol, do not leave a space between the unit and quantity (e.g. US$500).

Examples of currency formats are listed below. You can also refer to the official ISO-4217 website for currency codes for all other countries.

Country Currency Symbol Currency Code
Australia Australian dollar AU$ AUD
Canada Canadian dollar CAN$ CAD
European Union euro EUR
United Kingdom pound/sterling £ GBP
United States US dollar US$ USD 

Measurement: symbols

When a number is associated with a unit of measurement, it is normally given as a digit, for example 5 volts, 3 MB. Leave a space between the figure and unit of measurement. However, the money symbol and percent symbol are always closed up. (If a currency code is used rather than a money symbol, leave a space between it and the figure.)

  • 10 MB, 20 kg, $24, 10%, USD 342 million

Abbreviated units of measurements have no full stop and take no s in the plural.

  • 10 MB, not 10 MBs

With abbreviations, capitalisation is important, for example Mb means megabits, but MB means megabytes.

Never allow the unit and amount to be separated over a new line.

Time of day

Generally, spell out even, half and quarter hours:

  • The meeting continued until half past three.
  • I’ll be there by ten o’clock.

Use figures for when you want to emphasise the exact time:

  • 6.20 a.m. (Note that in American English a colon is used between hour and minute.)

When a 24-hour clock is required, use the following style:

  • 04:00; 12:00; 15:53


I wonder if CTM in Brookvale, Sydney Australia, still has NO PICK UP’S ON SATURDAY’S.

Misuse of the apostrophe is common and give a negative impression of an author’s writing skills…

(from - Richard writes: Here's some real exclusivity! A bookstore in Mt. Eden, Auckland, New Zealand is holding a festival for one writer and one reader. I wonder who the lucky pair were.

Here are some rules that are not difficult to remember.

Expressions of Time

It was previously conventional to use an apostrophe in expressions of time involving a plural reference, such as:

  • Six weeks’ time
  • Three months’ wages

The apostrophe is now often left out, i.e.:

  • Six weeks time
  • Three months wages

The sense of these phrases tends to be more descriptive than possessive.

When the time reference is in the singular, however, the apostrophe should be retained to help mark the noun as singular:

A day’s journey, the year’s cycle

– Source: Style Manual, 6th edition.

It’s vs. its

It’s not correct to leave the apostrophe out if it’s a matter of ‘it is’.

It’s the cat’s habit to chase its tale (this is a cat with character). It is: it’s. The nose belongs to it: its nose.

1.         It’s = It is

2.         Its = belonging to it

Numbers and dates

  • Numbers and dates, such as in his 60s, fly 767s, during the 1980s—All the regional style manuals including the Chicago Manual (2003) agree on this [no apostrophe]. Apostrophes are usually there in the plural of single numbers, as in All the 2’s and 3’s were missing.
  • If there are two or more owners, add ‘s’ then an apostrophe.


Acknowledgement of others’ views… (Plural ‘others’—the views belonging to others)

The candidates’ views were not considered. (Plural of candidate)

  • If there’s one owner, add an apostrophe and then ‘s’.

… initiatives or strategic ways in which the successful candidate’s learning could be leveraged.

  • The exception to this rule is:

For words which form their plural by changing internal letters (instead of adding ‘s’), the apostrophe comes before the ‘s’.

It was the children’s turn to wash up.

Some other words which follow this rule are: men, women, people.

Joint ownership or association is shown by placing the apostrophe -s on the second of the two owners;

  • His mother and father’s legacy
  • Rutherford and Bohr’s atom

In contrast, where the ownership is not joint, each name takes and apostrophe;

His mother’s and father’s voices

Sibelius’s and Grieg’s works


[Content of this post © Ascension Editing 2010]