It took eight years to finally come to a resolution on how to configure numbers accurately. Or was it 8 years? Does it really matter whether an author writes eight or 8? Well, actually it does. But, like anything else, there are rules to dictate how numbers should be written, whether to use the numeral form or spell out the numbers. And, like anything else, there are multiple exceptions to every rule.

Generally speaking, the consensus is to use the numerals for anything 100 and above. Under 100, you spell out the numbers. So, the correct form of eight years, should be eight years, not 8 years.

Another example:

Wrong: She gave Alan 1 large bag of chocolate Easter eggs.

Right: She gave Alan one large bag of chocolate Easter eggs.

However, both of the following examples would be right

Sally won over two thousand dollars in the lottery.

Sally won over 2,000 dollars in the lottery.

Then, there is the case of ordinal numbers, those with extensions like ‘st’ and ‘th’. Again, up to 100 for military units and street names, write out the number. (Note: newspapers and military publications may have their own form of writing ordinal numbers.) For example:

The Eighty-eighth Airborne Division held higher honors than the 102nd Airborne Division.

Annie’s Emporium on Fifth Avenue was similar to her sister’s on 140th Street.

This, of course, creates another dilemma. There is a rule against mixing writing numerals and spelling numbers on the same line or even in the same paragraph. So, what does a writer do? How about this:

Annie’s Emporium on Fifth Avenue was similar to her sister’s on one hundred and fortieth Street.

A little more cumbersome for both the author and the reader. Here’s a list of ordinals and how to write them out:

0       no ordinal for zero         
1st      first                              
2nd     second                          
3rd     third                             
4th     fourth
5th     fifth
6th      sixth                            
7th     seventh                       
8th     eighth                         
… and so on…

20th    twentieth
21st    twenty-first

… and so on…

100th one hundredth
1000th one thousandth

… and so on…

To finish off, here are some stringent rules regarding numbers:

Always spell out a number if it begins a sentence.

Always hyphenate compound numbers like twenty-five, etc.

Spell out simple fractions and hyphenate them, like one-quarter.

Treat large numbers paired with other numbers in the same way you would treat other numbers, like nine million years ago, instead of 9 million years ago. Exception: if large numbers include decimals, write them as numerals, like 10.5 million years, instead of ten-point-five million years.

Use words rather than symbols, like percent instead of %, number instead of #1, dollar instead of $. And, don’t hyphenate money amounts between the number and the word dollar, like two dollars or twenty-two dollars. However, the exception is when defining the specific currency, like a two-dollar bill, or a two-hundred-dollar fine.

Use numerals for time, like 5:45 a.m. instead of five-forty-five a.m.

Use lower case letters for a.m. and p.m. and a period after each one.

Dates can be written in a number of ways. The twenty-fifth of December or the twenty-fifth are both valid and acceptable forms. December 25th and December 25, 2015, are not acceptable forms (Always spell out numbers in dialogue: We can’t wait until December twenty-fifth.)

Do not use a hyphen (dash) to connect two dates. He was going to be away from August 5-September 1. Should be: He was going to be away from August 5 to September 1.

Decades may be written as either numbers or words (but be consistent) – the roaring twenties or the roaring ‘20s are both acceptable. Note that there is no apostrophe between the number and the ‘s’.

Write telephone numbers in numerals.

Write product names like this: 7Up, 7-Eleven.

Heights may be written in a variety of ways. For example:                                 

He was six feet two inches tall.

He was six feet two.

He was six-two.

And there are always exceptions, like:

You may alternate numerals and numbers that are written out when you have numbers side-by-side. It makes an easier read. Example:

She prepared 20 twelve-inch round pie shells.

We tied together 4 six-foot stakes.

There are more rules and more exceptions. If in doubt, ask an editor or research the many resources available online. Most important – be consistent. Don’t write: In Grade 8 I learned the importance of eight events in history. The correct form would be: In Grade eight I learned the importance of eight events in history. But, if you were being consistent in using numerals throughout your story, then this would be equally correct: In Grade 8 I learned the importance of 8 events in history.

And, lastly, have fun with the numbers game.