Writing Numbers: How to Write Numbers Correctly (Examples)

Are you confused about how to write numbers correctly in your writing? Should you spell them out or use numerals? After reading this article, you'll wonder no more.

You have several options when writing numbers: spell them out or use digits. Which one you go for will depend on common number writing conventions and the style guide you're using.

This article is part of our free online Grammar Book.

What Are the Different Types of Numbers?

Before diving in, let's review the different kinds of numbers. The two main types are cardinal and ordinal numbers.

• Cardinal numbers are what you think of when you think of numbers: one, two, three, etc. They tell you how many of something there is, and you use them for counting. 

Here are some examples of sentences that use cardinal numbers:

I have one dog and three cats.

The concert was attended by over a thousand people.

There were nine of us in the office this morning. 

• Ordinal numbers tell you what order things are in or their rank or position: first, second, third, etc. As the word 'ordinal' suggests, ordinal numbers allow you to put things in order.

Here are some examples of sentences that use ordinal numbers:

She came second in the competition. 

I'm the third tallest girl in my class.

Our offices are on the sixteenth floor.

There are also other types of numerals, such as nominal, iterative, multiplicative, and many more.

How to Write Numbers Correctly

Now that we've established what numbers are and the different types, let's learn how to write them.

You can either spell out a number as such:

thirty-one

Or you can write it in numerals, as such:

31

This can be a little tricky because different style guides follow different rules. Your best bet is always to consult your chosen style guide if you have one. If you don't, this article will provide some guidance in the form of commonly used conventions for writing numbers.

I'll use the words 'numeral, ' 'Arabic numbers,' 'digits,' and 'figures' interchangeably to refer to numbers ('1') and the terms 'spell out' and 'letters' to refer to words written out ('one').

Writing Cardinal Numbers

I'll start by outlining standard practice for cardinal numbers. Again, these are just general guidelines that are most commonly agreed upon, and you can feel free to deviate from these. The key is to remain consistent: pick a style and stick with it.

Spell the First Word

Firstly, it's standard practice to spell out a number if it's the first word in the sentence, which trumps any other rule. So, for example, even though dates are usually written in numerals, if it's the first word in the sentence, you should spell it out.

If you'd prefer to write it in numerals for better aesthetic and readability, you can always rephrase your sentence so the date isn't the first word.

For example:

Nineteen-ninety nine was a big year for us.

A big year for us was 1999.

Small and Large Numbers

A good rule of thumb is to spell out numbers zero through nine and use numerals from there onwards. However, some style guides disagree with this, such as the Chicago Manual of Style, which suggests that you spell out the numbers zero through one hundred and use numbers from 101 onwards.

Just pick the rule that makes the most sense to you!

Years, Decades, and Centuries

Generally, it's best to write specific years in Arabic numerals.

For example:

I was born in 1972.

Spell out decades in formal writing, but know that it's also safe to write them in numerals. Just remember there's no apostrophe before the 's.'

For example:

I love the fashion in the sixties.
I love the fashion in the 60s.
I love the fashion in the 1960s.

The same rule applies to centuries: spell it out in formal writing, but numerals are acceptable the rest of the time.

This is the twenty-first century, you know.
This is the 21st century, you know. 

Percentages

Write percentages in figures followed by the percent sign.

For example:

I'm about 80% certain this deal isn't going to go through.

Units of Measurement

Write units of measurement in figures:

I weigh 65kg.

The park is 100m to the right.

He ran the race in 3h45mn.

Money

Write money in figures, too:

I've only got $1 to my name.

The house is about 10 grand over my budget.

You're 5 cents short.

Fractions and Decimals

Fractions aren't technically cardinal numbers, but we use a mixture of cardinal and ordinal numbers to spell them out. Depending on the context, they can be written in numerals or letters. Usually, if it's a scientific or mathematical text, the fraction will be written in figures, but if it's any other kind of text (such as an essay discussing research findings,  you'll most likely want to spell it out.

About one-fifth of the class is behind in Mathematics. 

Write decimals using numerals. If you have to spell it out, round it up to the closest number:

1.25

one

Unless it is half, then you can write:

one and a half.

Multiple Numbers in a Sentence

If your sentence has two numbers in a row, you should use different formats for each one so they don't get mixed up.

There are five 4-year olds in my class.

If a sentence has multiple numbers and one of them requires numerals, then use numerals for all of them, even those under 10.

The farm has 3 goats, 11 cows, 5 horses and 8 pigs.

Using Hyphens in Numbers

Sometimes when spelling out numbers, you'll need to use a hyphen. We use them to connect two-word numbers. Hyphenate all compound numbers from twenty-one through ninety-nine.

There are one thousand, three hundred and fifty-six children that go to this high school.

Als,o hyphenate fractions:

About two-thirds of the population have tried meditation at least once.

Writing Ordinal Numbers

Now we've covered how to write cardinal numbers, let's learn how to write ordinal numbers. First of all, you might want to know how to make them.

For the most part, you create ordinal numbers by adding 'th' to cardinal numbers.

That's with the exception of the following:

• first
• second
• third
• fifth
• eighth
• ninth
• twelfth

Other than those, it's pretty smooth sailing:

• fourth
• sixth
• seventh
• tenth
• eleventh
• thirteenth
• fourteenth
• fifteenth, and so on.

To write them in numerals, it's even easier: you add the last two letters of the written number to the end of the cardinal number:

• First → 1st
• Second → 2nd
• Third → 3rd
• Fourth → 4th
• Fifth → 5th

And so on.

So what are ordinal numbers used for? The answer is they are pretty much used for any kind of positioning or ranking. That could include floors of a building, dates, fractions, centuries, positions in line,e or lists.

When should you spell vs use numerals with ordinals? The answer is the same as with cardinal numbers: spell them out from 'first' to 'ninth,' and then after that, use numerals.

Concluding Thoughts

That concludes this article on writing numbers correctly. I hope you now feel more confident using numbers in your writing.

Let's summarize what we've learned:

• The two main types of numbers are cardinal and ordinal.
• You can either spell out or use numerals when writing numbers.
• It's generally agreed upon that you should spell out numbers zero through nine and then switch to digits.
• Different style guides have different rules.
• Stay consistent with the rules you decide to follow.

If you enjoyed this article, check out our Grammar Book, a free online database of articles to help you with your writing, just like this one. Check it out!