How to write numbers
We all know the rhyme 1, 2, buckle my shoe. 3, 4, knock on the door.
Or should it be One, two, buckle my shoe. Three, four, knock on the door?
Though a reader might not be conscious of it, if numbers are not formatted correctly and consistently, your writing will look unprofessional. This article is about how to make numbers and numerals in formal and informal writing consistent and easy to read in New Zealand English writing.
Note that these guidelines don't apply to technical or scientific writing – refer to the appropriate style guide for these styles.
The most common question for writing numbers, whether it’s fiction, non-fiction or business documents, is whether to spell out the number or whether to use the numeral, but there are also other rules and exceptions to consider.
As always, first check if your organisation has a style guide, and follow that. If there is no style guide, then the guidelines below will help you decide how to write numbers in New Zealand English.
To spell out or not to spell out
The first thing to consider is what kind of text you are writing and who will read it. The more numerals, rather than spelled out numbers, the more technical the text appears. Sometimes the decision will be made with space restrictions in mind.
There is no set rule; there are just guidelines. But it is, as always, important to be consistent within the document, and across all you content.
For literary writing, it was traditionally preferred to spell out all numbers, but today, except in certain circumstances (see the rules and exceptions below), it is acceptable to:
spell out numbers one to ninety-nine
use numerals for 100 and over
For business writing, it depends on how technical your document is. A general rule of thumb, with the exceptions below, is to:
spell out from one to nine
use numerals for 10 and over
Websites tend more towards business writing, and numerals are used more than spelled out numbers.
Consistency within a paragraph
In a paragraph with numbers that sit in both ranges (either above and below 10, or above and below 100), use all numerals in that paragraph only. The rest of the document will continue to use the guidelines above.
The number of pages in each chapter in his book were 80, 101, and 130 respectively.
not The number of pages in each chapter in his book were eighty, 101 and 130 respectively.
They picked 45 apples from one tree, 74 from another, and 104 from the third.
not They picked forty-five apples from one tree, seventy-four from another, and 104 from the third.
However, when two groups of numbers are being used in the same sentence. It is easier and quicker to understand if you spell out one group and use numerals for the other.
It is thought that 70 per cent of people over the age of eighty like to do crosswords, whereas only 50 per cent of people between the ages of twenty and eighty do.
not It is thought that 70 per cent of people over the age of 80 like to do crosswords, whereas only 50 per cent of people between the ages of 20 and 80 do.
Rules and exceptions
At the start of a sentence
A number should always be spelled out at the beginning of a sentence, or you can rewrite the sentence to avoid the numeral at the beginning of the sentence. Numerals can be used in the rest of the sentence.
Fifty-nine per cent of children like beans, but only 32% like Brussels sprouts.
not 59% of children like beans, but only 32% like Brussels sprouts.
Rewrite sentences with a date so that the date isn't at the beginning of the sentence.
In 1949, ...
not 1949 was the year ...
not Nineteen forty-nine was the year ...
Rewrite sentences starting with a number with a decimal so that the numeral isn't at the beginning of the sentence.
Each hour, 2.154 people take public transport from the suburbs.
not 2.154 people take public transport from the suburbs each hour.
not Two point one five four people take public transport from the suburbs each hour.
Punctuation
Use a comma to mark the thousands in numbers with four or more figures.
1,234
2,468,158
For very large numbers, it’s clearer to write million or billion after the decimal.
4.2 million not 4,200,000
1.524 45 billion not 1,524,450,000
For long numbers that include a decimal, use a thin space instead of commas.
12 456.524
Compound numbers use hyphens when spelled out.
Forty-five
One hundred and thirty-five
In her hundred-and-second year
Spacing
In most forms of writing, it is clearer to insert a space between the numeral and the abbreviation of the unit of measurement. Though it's now also becoming accepted to close up the space in less formal texts.
7 kph
52 km
When using symbols, it is always closed up (no space before the unit).
7%
32°C
$5
25c
Number ranges and elision
An en dash without spaces is used to show missing numbers (elision of numbers), for example with page numbers or years. However, don’t elide numbers in headings, or with vital information such as the years of birth and death.
Use the fewest figures possible without losing clarity.
30–34 becomes 30–4
2001–2005 becomes 2001–5
132–136 becomes 132–6
If it’s not clear with one numeral, add more numerals.
132–145 becomes 132–45
2001–2025 becomes 2001–25
1459–1531 becomes 1459–531
Don’t elide years that go across a century.
1985–2010
not 1985–10
Write BC years in full for clarity.
765–567 BC
When writing about a range of years, use from … to or during, not both.
The war from 1939 to 1945
The 1939–45 war
not The war from 1939–45
The period between 1939 and 1945
not The period between 1939–45
The period 1939–45
With ranges that include a negative number, it’s better to use words rather than a dash.
The temperature ranged from -25 to -2
not The temperature range was -25–-2
If necessary for clarity and meaning, repeat the figures.
1–2,000 means from 1 to 2,000
1,000–2,000 means from 1,000 to 2,000
With a unit of measurement, don’t repeat the unit unless it’s usually closed up.
3–5 km
2°–5°
3%–10%
Approximate numbers
If a number is used approximately, then spell it out. If it is used precisely, use numerals.
New Zealand has a population of just under five million people.
New Zealand has a population of 4.88 million people
He has about a thousand sheep.
He has 1012 sheep.
Numbers used indicatively (not precisely) should be spelled out.
He brought a dozen toys with him to school. [not 12]
We must have told him a hundred times he didn’t need that many toys. [not 100]
Thousands of birds were wading in the pond. [not 1,000s]
Ordinal numbers
Ordinal numbers indicate a place in a series. First, second, third, fourth, etc.
Traditionally these were spelled out from first to ninety-ninth, but today it is more common to see them spelled out from first to ninth, and numerals for numbers higher than that.
We were the first in the queue.
The book was set in the 16th century.
It was their 50th wedding anniversary.
It was her 21st birthday.
Superscripts for ordinals are no longer used in New Zealand English, though you will need to overrule Microsoft Word’s autocorrect to to make sure it's not superscript.
21st century
Fractions
Fractions are usually spelled out in writing.
Two-thirds of the children wore hats.
About half of all children like to wear hats.
Fractions that are long and awkward when spelled out can be written as fractions in informal writing.
It took them 2¾ hours to get to the top.
But in formal writing: It took them two and three quarters of an hour to get to the top.
Hyphens in fractions are preferred, but can be left out.
Two-thirds
Two thirds
A three-and-a-half-hour walk.
Don’t use a hyphen between the whole number and the fraction.
One and two-thirds
If abbreviations or symbols are used, the number is always in numerals, and fractions are shown as decimals.
The sign was 4.25 km away.
The sign was 4.25 kilometres away.
not The sign was 4¼ km away.
Age
Use numerals for age.
He was 25 years old when he adopted three dogs.
But in informal writing, it is acceptable to spell it out.
The two-year-old child
The thirty-three-year-old student
When using ordinals or decades, spell it out.
In his forty-fifth year
In her teens
In his twenties
Units of measurement
Spell out numbers with spelled out units of measurement, but numerals can be used with abbreviated units of measurement or spelled out forms.
51 km
fifty-one kilometres
not fifty-one km
6 km/h Note: the form using the solidus (/) is preferred, though kph is also common.
6 kilometres per hour
52 mm
52 millimetres
Money
Money is usually shown with figures, but can be spelled out in informal text.
He had ten dollars left.
He had a $10 note in his pocket.
Larger amounts can be combined with symbols and words.
$2 million
NZ$5 billion
$5 b, though some styles prefer $5b
Cents, use the symbol closed up.
50c
Only add the .00 if needed in context.
He had $10.
She had $15.00 after he had received $5.50 back.
Percentages
Percentages are usually written as figures, regardless of whether you use the % symbol or write out per cent, or how high the number is.
Only 2 per cent of the committee voted for him.
Just over 56% of commuters prefer to walk.
They predicted 4% would vote no.
Per cent and percent are both used, though per cent is preferred in British English and percent is preferred in US English.
Exceptions
There are some exceptions to the rules on when to spell out or use punctuation.
Street numbers: 5467 Main Street
Zip/Postal codes: Christchurch 4521
Page numbers: pp 2564–6
Years: 2020, 24000 BC
Parts of books: p. 24, Chapter 9
Scores of sports games: they won 3–2
Distances of races: the 400 metres
Highway numbers: SH1, SH79
Phone numbers: (02) 123 4567
What next?
If you have written content in New Zealand English and this all sounds overwhelming, I can help.
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Sources:
Hughes, J., & Wallace, D. (2010). Fit to Print : The Writing & Editing Style Guide for Aotearoa New Zealand. Wellington, New Zealand: Dunmore Publishing.
Oxford University Press, (2016). New Oxford Style Manual (3rd ed.). United Kingdom: Oxford University Press.