1.22 Numeracy

Different Styles

The many editorial style manuals such as APA, MLA, and Institute of Electrical and Electronics Engineers (IEEE) have different rules for spelling out numbers in text. Some use words to describe amounts while others use numerals.

Below are the general rules used in APA.

APA General Rules

Write out numbers from 0 – 9

This rule applies to both cardinal numbers (whole numbers) and ordinal numbers (first, second, twenty-fifth)

• Beginning next week, four of our employees will be participating in a reduced work week.
• In the survey, our company ranked third in the customer service section.
• Nine employees opted for earlier retirement.

Use the numeric form for numbers over 9.

• Beginning next week, 24 of our employees will be participating in a reduced work week.
• In the survey, our company ranked 23rd in the customer service section.

Avoid beginning a sentence with a number.

Be consistent with mixed numbers

If a sentence includes numbers over and under 9, use the numeric form for both numbers.

• Several employees requested extended vacation time: 2 accountants and 11 sales representatives.
• Our customer service desk is operated by 3 managers and 14 travel information specialists.

Apply the rules below for fractions, decimals, and percentages

Fractions

Write common fractions such as a half or a quarter. Use numeric form for unusual fractions.

• Our manager noted that half of our employees have activated the new security program.
• Surprisingly, 7/8 of the product is merely tap water.

Decimal and Percentages

Use numbers to express decimals and percentages.

• Our study indicates that 74% of respondents are concerned about cyber security.
• The researchers concede a 2.75 to 3.35 probability range of error.

Times and Dates

Use numbers to express times and dates.

• We were able to meet with the supervisor for 45 minutes.
• The product development team submitted the report 3 months ago.