The following information is an abridged version of the style and formatting guidelines found in the Publication Manual of the American Psychological Association, 7th ed. (2019) and Purdue Online Writing Lab. This sheet is to serve as a ready-reference; more in-depth descriptions can be found in the handbook. Remember to always consult your professor for specific instructions when formatting a paper.
Numbers
When to Use Numerals
Numbers 10 and Above
Use numerals to express numbers 10 and above and words to express numbers below 10.
Example
- 10 years old
- 12th clinical trial
- 45% of the deficit
- five groups
- nine questions
- 145 participants
Numbers that immediately precede units of measurement
Use numerals to express numbers that immediately precede units of measurement.
Example
- 5-mg dose
- 25 units
- 2.53 cm
Numbers that Represent Specific Quantities
Use numerals to express numbers that represent specific quantities (times, dates, parts in a numbered sequence, and other finite measurements).
Example
- 1 hr 15 min
- 6 on a 7-point scale
- Until 5 p.m.
- Chapter 12
- 4 and 5-year-olds
Other Numbers
Use numerals to express numbers that represent statistical or mathematical functions, fractional or decimal quantities, percentages, ratios, and percentiles and quartiles.
Example
- 4 times the amount
- 0.75 cm
Note: Use a zero before the decimal point with numbers that are less than 1. Do not use a zero before the decimal point in correlations, proportions, and levels of significance, as they can never exceed the value of 1.
When to Write out Numbers
Numbers that Start a Sentence, Title, or Text Heading
Write out the number if it starts a sentence, title, or text heading (APA guidelines suggest rewording a sentence whenever possible to avoid starting with a number).
Example
- Ten students earned an A, but 10 others received a B or below.
Inexact or Approximated Numbers
Write out the number when it is inexact or approximated.
Example
- Her symptoms began approximately three years ago.
Common Fractions and Numbers Included in Proper Nouns
Write out the number for both common fractions and numbers included in proper nouns.
Example
- three-fourths of the participants
- The Ten Commandments
Tables
Use tables in your paper as a supplemental tool to clarify information that may be difficult to understand without a visual. Tables should be concise, logical, and easy to understand. APA provides very specific guidelines on the proper uses for and ways to format tables. For more information see Chapter 7.
General Information
- Use Arabic Numbers to number your tables as they appear in your paper.
- Use column headings and subheadings to make your table clear.
- Use notes below your table to add any information that will help the reader understand the table.
- Italicize the title and position it below the table number.
- When referring to a table in the body of your paper, refer to its number.
Example
- Correct: As seen in Table 12, the heat index is higher in…
- Incorrect: The table found on page 12… OR The table below shows…