On the surface, numbers are one of the easier elements of the English language. Since most languages around the world use Arabic numbers, many non-native English speakers can write numbers in English without learning any new information. But some situations require numbers to be written out as words, fractions, or ordinal numbers. It all can start to complicate things.
Fortunately, once you learn the basic rules for written numbers, it’s easy to know when and how to write numbers in English.
To get started, let’s first take a look at the most common way to write numbers in English: cardinal numbers.
How to Write Cardinal Numbers
Cardinal numbers denote the precise quantities of things. You likely encounter cardinal numbers on a daily basis. Whether you’re checking your bank account or making a grocery list, you’ll need to know how to read and write cardinal numbers. However, it’s important to note that there are two distinct ways to write cardinal numbers in English:
The list above shows how the numbers 1-10 are usually written. However, they can also be spelled out as words:
In the list below, you can see how more numbers are written in English as words:
After 20, you will start using hyphens in conjunction with 1-9, repeating this pattern until you get to 99:
While 21-99 require hyphens (and any numbers that include them, like 125 or 642), words that signify larger quantities do not require hyphenation:
When should you use cardinal numbers?
Cardinal numbers are used for determining the quantity of things in whole numbers (no fractions or decimals). A cardinal number answers the question “how many” and can be used in relation to anything that can be counted.
For example, you can say that you have 3 apples or three apples. Similarly, you can say that you have $20, 20 dollars, or twenty dollars.
How to Write Ordinal Numbers
Ordinal numbers in English refer to a specific order of things. These are especially common when recording the date. However, they can also be used in many other situations.
In essence, ordinal numbers are simply cardinal numbers with a two-letter designation. It shows that you’re talking about order in a sequential list.
Just like cardinal numbers, ordinal numbers can be written as numbers or as words:
For 21st-99th, you always use the two-letter signifier that corresponds to the second digit in the number, like this:
Ordinal numbers larger than 99th follow the same rules as cardinal numbers, insofar as hyphens are not used to denote numbers like 100th or 1,000th:
When should you use ordinal numbers in English?
Ordinal numbers are most commonly used to write dates in English. For example, rather than writing “January 3,” you should write “January 3rd” or even “the third of January.”
Ordinal numbers are also used to refer to repeated events—especially those that happen on an annual basis. For example, you can say that it is your grandfather’s 80th (eightieth) birthday, your 10th (tenth) wedding anniversary, or the 21st (twenty-first) annual dog show.
Finally, ordinal numbers are used in competitions (1st place, 2nd place, 3rd place, etc) or any situation in which a sequential list is required.
How to Write Fractions and Decimals
When you can’t use whole numbers, you’ll need to write using either fractions or decimals. Fractions work much like ordinal numbers, though you will need to use hyphens when writing them out as words:
If the numerator in a fraction is more than one, you will need to add an “s” to the end of the two-letter signifier:
As you can see, writing out larger fractions as words can get a little complicated, as you may need to use more than one hyphen. This can make it confusing to know which number is the numerator and which number is the denominator. So, if writing out fractions requires two or more hyphens, it is best to simply write the fraction using numbers.
While decimals are written differently than fractions when using numbers, they are written the same as words:
When do I write the number in English vs. writing it out as a word?
There are no specific rules regarding when to spell out numbers in English. That being said, if you’re writing a number between 0-10, you should generally write it as a word (though this is not a strict rule in English grammar). For numbers larger than 10, you should write them as numbers.
This is mostly due to the fact that, when spelled out, larger numbers can take a great deal of time to write.
How you write numbers will also depend on the context. For example, when you write a check, you will need to write out numbers as words AND as numbers. However, in most situations, you can simply write numbers in English without having to spell them out as words.
We hope you found this guide helpful! For more English tips and grammar lessons, consult the Magoosh website today!