How to Write Numbers - When to Use Words

How to Write Numbers in English

How to write numbers in English can be confusing. Knowing when to use numbers and when to use words to represent numbers can be tricky for English learners and native English speakers. There are a few rules as well as a lot of opinions. Consider what follows here to be guidelines.

First, consider a few definitions: A number is a concept used in counting and calculating. A numeral is a word, figure, or group of figures denoting a number. However, for ease of explanation in these guidelines, when I refer to “numbers”, I speak only of symbols such as 1, 2, 3, etc., as this seems to be the standard term most people use to refer to these symbols. Otherwise, I will refer to “words” such as one, two, three, etc.

General Rules

There are a few rules that are agreed to by most publications:

The primary consideration of whether to write numbers or words is clarity. The sentence or passage must be easy to understand without any chance of confusion or misunderstanding.
Write numbers zero through nine (one-digit numbers) as words. Now, this rule is not unanimous. Both the Chicago Manual of Style and Grammarly suggest writing zero to one hundred as words for non-technical writing because these numbers can be distracting and interfere with the flow of the text.
Write round numbers, such as hundreds, thousands, millions, billions, etc., in full.
An English sentence should never begin with the word “number” or actual numbers. The only exception to this rule is a year. E.g. It is okay to start a sentence with “1950”.
The entire number must appear on one line without continuing to the following line.
Consistency is of prime importance. As mentioned earlier, much of what is to follow are guidelines only. Whichever way you apply these guidelines must be consistent throughout the work.

Now, let’s get into more specific use of numbers in writing.

How to Write Time in English

You can find time written in many different ways. Only two common, approved, and practical ways to write time exist. However, slight variations can be found, such as using a period instead of a colon, adding periods to AM and PM, or leaving them out of a.m. and p.m. Sticking to one of the two ways below and consistently using whichever one you choose is better. I recommend #1 as it is less intrusive or distracting in the sentence, but the choice is yours.

Two Accepted Ways to Write Time

1. Lowercase a.m. and p.m. with periods:

Both a.m. and p.m. require punctuation because “am” is a word unto itself, and p.m. for consistency.
It would appear that this is the most common way.
Many prominent style guides approve this method, including The Chicago Manual of Style and AP.
Always use numbers with a colon and a space between the time and a.m. or p.m., e.g., 8:30 p.m.
If an exact hour, write the time without the colon and the last two digits, e.g., 7 a.m.
Time intervals entirely in the a.m. or p.m. require the a.m. or p.m. after the end time only, e.g. 3:30-11:30 p.m.
Time intervals that cross over noon or midnight require the a.m. or p.m. after both the beginning and the end times, e.g., 9 a.m.-5 p.m.

2. Uppercase AM and PM with no periods:

Uppercase AM and PM appear to many people to be too boxy and distract from the flow of the text.
The only two differences between this way of writing time and number 1 above, AM and PM, are uppercase letters, and there are no periods.
The examples above would be the same, except with capital letters for AM and PM and no periods, e.g., 8:30 PM, 7 AM, 3:30-11:30 PM, and 9 AM-5 PM.

Two Impractical or Nearly Obsolete Ways to Write Time

1. Small uppercase AM and PM with or without periods:

This is a compromise between numbers 1 and 2 above.
It is impractical because small uppercase letters are not available with all fonts or in all programs.

2. Let’s call this way “Old Style”:

This method is from the time of analog timepieces before digital became the norm.
At least in writing, it’s impractical and almost obsolete as the language doesn’t relate to digital technology.
This language is based on a shape where you could imagine cutting it into halves or quarters.
O’clock is used only on the hour, e.g., nine o’clock.
Half past is used only for the half-hour, e.g., half past three.
A quarter to, a quarter before, a quarter of, e.g., a quarter to five, a quarter before five, a quarter of five.
A quarter after, a quarter past, e.g., a quarter after two or a quarter past two.

Avoid Redundancies When Writing Time

Now, let’s look at some definitions and redundancies in telling time or, specifically, in writing time.

The abbreviations a.m. and p.m. stand for ante meridiem and post meridiem, which translate into before noon and after noon, respectively.
Do not use 12 p.m. and 12 a.m. These notations can be confusing because 12 is the exact time to which the a.m. and p.m. refer and, therefore, cannot be before or after themselves. Use noon and midnight.
Do not use 12 noon and 12 midnight. These notations are redundant. Use noon and midnight only.
Do not use 4 p.m. in the afternoon. It is redundant. Use 4 p.m.
Do not use o’clock with a.m. or p.m. These references refer to different ways of telling time and are not compatible.

How to Write Dates in English

The United States is different from other countries in terms of writing

USA MM/DD/YYYY

Most of the Rest of the World DD/MM/YYYY

This difference can be a problem, especially for Canada, which borders the United States and has many cross-border dealings and communication, e.g., 04/11/2020. Does this mean April 11, 2020, or November 4, 2020? Well, there’s no way of knowing for sure. You may get a hint from the surrounding context or depending on the current time of year.

The current suggested international standard is YYYY/MM/DD. This format would be unambiguous but only valid if all countries agree. There could still be confusion as the writer may reverse the month and the day.

The only way to be sure of the date is to spell it out in full:

April 24, 2021, or even Saturday, April 24, 2021.

Write decades in one of the three following ways: e.g., the ’50s, the 1950s, or the fifties.

Write centuries in one of the following three ways: e.g., the 1900s, the nineteen hundreds, or the twentieth century. (Note: All three examples for the century refer to the same century.)

Money

There are specific rules regarding numbers about money and various currencies:

Currency symbols are to be placed directly in front of the amount with no space between, e.g., $153.27
Commas separate thousands, e.g., $93,239.14
Decimal points separate dollars and cents, e.g. $2,332.79
Don’t write out the currency when you have already written a currency symbol before the amount; that is redundant, e.g., $237 dollars.
A decimal point must be preceded by at least one digit and followed by two digits, e.g., $0.99, not $.99, and $957 or $957.00, not $957.

***Piggy Banks and a Gold Dollar Sign***

Temperature

Abbreviate Celsius as C; write temperatures with a number, degree symbol, and Celsius symbol, and with no spaces, e.g., 0°C (water freezes), 100°C (water boils), 19°C, -7°C

Abbreviate Fahrenheit as F; write temperatures with a number, degree symbol, and Fahrenheit symbol and with no spaces, e.g., 32°F (water freezes), 212°F (water boils), 75°F, -40°F

The above essay is for entertainment and English language study only. For suggestions on how to use this post to improve your English reading and listening comprehension, click here.

How to Write Numbers – When to Use Words