General Uses Of Figures And Numbers
If you can write a number with one or two words, you should do so (certainly anything under 25 should be written in words). If it requires more than two words, you may use digits to express the number.
The play is for ages 5 and under.
The play is for ages five and under.
His great-grandmother was born in nineteen-oh-three.
His great-grandmother was born in 1903.
Don’t mix-and-match digits and words unless required for purposes of clarity.
The play is for ages five to 105.
The play is for ages five to one hundred and five.
Because five must be written as a word, we take our cue from it and write 105 in words.
Don’t start a sentence with digits.
2012 will be the end of the current Mayan calendar.
The year 2012 will be the end of the current Mayan calendar.
Two-thousand and twelve will be the end of the current Mayan calendar.
When using figures to write a decimal, put a zero before the decimal so the tiny dot doesn’t go unnoticed.
This year, our salaries have only been increased by .5%.
This year, our salaries have only been increased by point five percent.
This year, our salaries have only been increased by 0.5%.
Use digits when writing a date.
He was born on January fifth.
He was born on January 5th.
When writing approximate times, use words; when writing specific times, use digits.
The plane leaves around six o’clock in the evening.
The plane leaves at 6:19 in the evening.
Dinner is at five o’clock. (Despite being a specific time, this sentence uses words because – let’s face it – even in the strictest of households, meals aren’t timed to the minute.)
Addresses and other identifying numbers should always be written as digits.
I live at 39 Main Street.
Queen Elizabeth I was the head of the English church.
In business writing, use both words and digits so the meaning is clear.
The bearer of this card is entitled to one (1) free pizza.
This agreement will expire three (3) years after today’s date.