Per APA 4.31 to 4.38, write out numbers as words to express numbers up to nine (e.g., three, seven, eight), and use numerals to express numbers 10 or above (e.g., 11, 23, 256) .

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Use words to express numbers when...

• Beginning a sentence, title, or heading with a number.

  Seventeen computer programmers went out to dinner last night

• Dealing with a common fraction.

  The principal presented awards to three fourths of the student body.

Use numerals to express numbers in these situations...

• Numbers that represent time.

  She had been a nurse for 3 years.

  [Exception: spell out the numeral for approximations of time: about four days ago]

• Numbers that suggest a specific place in a series.

  Chapter 4 was considered required reading.

• Numbers that represent scores or points on a scale.

  The student scored a perfect 7.

• Numbers that precede units of measurement.

  Each post was roughly 2.45 ft apart.

• Numbers that represent a part of a mathematical expression.

  Teachers gave students ice cream if they scored in the top 5%.

• Numbers that represent exact sums of money.

  You owe me $5.

• Numbers that appear in an abstract