When do you spell out numbers in full words or use numerals in writing?
The rules for spelling out numbers can differ depending on which writing style guide you use.
But there is one rule with which everyone agrees. You need to be consistent in your use of numbers in writing.
Expressing numbers in writing
There are minor differences of opinion about how you can and should spell out numbers in writing.
Your selection of style will depend on whether you are writing fiction, articles, or technical writing.
Two general rules usually apply to all forms of writing, however.
One is that when a number begins a sentence, you should write the numbers in words.
The second is that numbers from zero through to ten are written as words, and larger numbers are written as numerals.
General rules for writing numbers
Because there are no hard and fast rules, there are many exceptions to the rule of when you should spell out a number.
But the following suggestions might help you in being more consistent in your writing of numbers.
For any form of writing, you should always check that you are not mixing different ways of expressing numbers.
1. Spell out numbers that start a sentence
When a sentence starts with a number, you should spell it out in full. It applies to both small and large numbers.
Ten children attended the party.
Nineteen eighty-seven was an eventful year for me.
Seventy-two people responded to my survey.
2. Hyphenate all compound numbers and fractions
When you spell out numbers from 21 to 99, always use a hyphen. But be careful with the number forty. There is no U. It’s a common spelling mistake.
The number forty-two is a famous number from the Hitchhiker’s Guide to the Galaxy.
She turns twenty-one next Saturday.
For fractions, it is always better to write them out in full.
It looks like two-thirds of the population will vote for her, according to the polls.
You need to answer at least three-quarters of the questions correctly to pass.
3. Ordinal numbers
Generally, you write ordinal numbers in full unless it is a date.
Tomorrow is their twenty-fifth wedding anniversary.
He finished third in the race, which was a great effort.
I’ll make an appointment for you on October 26th.
Decimal numbers are usually written in digit numbers for clarity and accuracy.
It was 87.2 degrees yesterday.
Our spending on advertising has risen by 4.7% this year.
I measured it, and it was only 3.8 inches long.
The world’s population is around 7.8 billion people.
When you use abbreviations for units of measurement, always use numerals.
The book is 3.6 cm thick.
I lost 7.5 kg last month.
You can use two forms for expressing time in writing. You can use digital time or o’clock.
I’ll meet you at eight-thirty pm.
Let’s get started at around eleven o’clock.
I should be home no later than seven-fifteen.
The most common form is to use numbers for years.
It’s best practice to write these words in full.
I was born in the fifties.
My favorite decade was the sixties because of the music.
The seventies will be remembered for the popularity of the colors orange and brown.
However, if you use digits, make sure you are consistent because there are different accepted forms.
Elvis was popular in the ’60s.
We moved here in the 90’s.
Life was tough in the 30s.
In writing, it is most common to use an ordinal number when writing out numbers for centuries.
We are living in the twenty-first century.
There was a plague in the fifteenth century in Europe.
Life was pretty tough in the nineteenth century.
9. Large numbers
You can use millions, billions, or even trillions in the US for big numbers that are even or decimalized.
The national debt is around three trillion dollars.
It cost them 3.1 million to build their house.
The government is investing billions in research.
But when it comes to precise long numbers, it is usually best to express them in digits for simplicity and clarity.
It was confirmed that 6,523 people attended the match.
The forecast annualized profit is expected to be $6,700,900.
During the first month of the crisis, 11,750 lost their job in the state.
10. Two numbers in a row
It’s always best to avoid this situation. But when it’s necessary, spell out one of the numbers to avoid confusing your readers.
A better solution is to re-write your sentence so you can separate the numbers.
There were 7 4 year-olds at the kindergarten. Confusing.
There were seven 4 year-olds at the kindergarten. Better.
There were seven children at the kindergarten, and they were all four-years-old. Best.
You are sure to find varying opinions about how to use numbers in writing correctly. However, as always, there are always exceptions to the rules.
Mignon Fogarty goes into a long explanation about the rights and wrongs in a podcast on numbers.
As I said at the beginning of this article, being consistent is the critical factor in good writing.
Take notes of how you intend to write your numbers, and keep to your selected styles.
If you use a good grammar checker, there is often a check for consistency for punctuation as well as for number variations.