Using Numbers in Writing
One problem writers often run into is what to do with numbers in their writing. This article offers tips on understanding when to write out the numerals in a sentence, as opposed to spelling out the numbers.
As with many concepts in the written language, there are always exceptions. Offered here are just some simple guidelines to help you along the way when dealing with numbers in your writing.

Less Than 10
Generally, if you’re using a number less than 10 in your writing, spell out that particular numeral.
I have three parties to go to next week!
My brother’s birthday is in two days.
I have six minutes until my favorite show comes on.

Goin Up From 10
For numerals of 10 or greater, you should write the numeral.
I can’t believe you turn 10 years old tomorrow!
There’s 23 days until summer vacation.
The angle is at 180 degrees.

The Beginnings of the Sentence
If a number begins a sentence, it must be spelled out.
Sixty percent of those surveyed agreed.
Seventytwo people attended the meeting.
Seven years ago, your baby sister was born.

Fractions, Fractions, Fractions
When writing a fraction, spell it out (and separate with a hyphen).
Only about onethird of the audience stayed the entire show.
There is onehalf of the game left.
There are threeeights of the pizza missing!

Mixed Fractions
Although rare, when using mixed fractions in writing, use the actual numerals.
I have driven 1½ times longer than you on this trip.

Percentages
If a percentage begins a sentence, spell it out. Otherwise, use the actual numerals.
Seventy percent of the country is not happy with their government's leadership.
About 70% of the country is not happy with their government’s leadership.

Decimals
In the rare event that you’ll use decimals in your writing, when you do, write it out in numbers.
In the month of July, there was 1.07 inches of precipitation.

It’s Time!
When writing the time, spell out the time when it is followed by “o’clock”; or when a.m. or p.m. are not written.
The movie starts at two o’clock.
I have to get up at eight o’clock.
The movie starts at 2 p.m.
I have to get up at 8 a.m.

Dates
Where dates and years are used, one should use numbers.
My birthday is June 2, 1978.
In 1992, my sister graduated from high school.
The concert is coming to Detroit on September 4, 2015.