0-9 is for Zero through Nine - When should you spell numbers out?

It's the eternal question. Should you spell your numbers out? As in:

I ate three cartons of Ben & Jerry's.

Or let numerals do the work? As in:

I ate 3 cartons of Ben & Jerry's.

The most important point to keep in mind is this: they were the teeny-tiny, single serving cartons, like the kind they sell for kids. Really small. That's all I'm saying.

As for spelling out numbers, the big rule is Be consistent. Pick a system and stick to it. If you're writing for a specific publication, ask for their style guidelines. Otherwise, your best bet is to follow APA style guidelines:

- Never start a sentence with a numeral:

Five little monkeys jumped on the bed.

NOT:

5 little monkeys jumped on the bed.

- Spell out numbers under ten, except when

• Referring to a specific address:

Number 5 Cherry Lane

• Naming an age, time, or date:

She left for London with her 8-year-old on August 6 at 9:00 am.

• Offering a precise measurement or reporting a quantitative result:

The gold weighed 5 grams.

Average of 4.5 on a 7-pt. Likert scale.

• Directing the reader to a specific page or figure in a book:

Table 4 on page 7.

• Grouping or comparing with numbers > 10:

According to 6 of 40 dentists surveyed.

6 cake mixes, 2 large cake tins, and 20 cans of soda.

- Use numerals for numbers 10 and above, except:

• At the beginning of a title or sentence:

Twenty Blackbirds: A Novel

• For common phrases

twenty-first century

• For common fractions:

three fourths of a pie

• When referring to very large sums. (In this case mixing words and numerals is preferred.)

a population of 315 million

- Do not stick to the rules where the rules will make things confusing.

• This phrase is confusing:

6 5-year-old boys

On a quick read it looks like:

65-year-old boys (= pretty weird)

• Either of the following is acceptable:

Six 5-year-old boys.

6 five-year-old boys.