Do I Write Out Numbers In APA Style? A Comprehensive Guide

Navigating the complexities of APA style can feel like learning a new language, especially when it comes to the seemingly simple matter of numbers. The rules governing how to present numerical data are surprisingly nuanced and often trip up even seasoned writers. This guide provides a comprehensive overview of the APA style guidelines for writing out numbers, designed to ensure your work is accurate, clear, and adheres to the expectations of the field.

1. The Fundamentals: When to Spell Out Numbers

The core principle of APA style is to enhance readability and clarity. Generally, there are specific situations where you must write out numbers in word form (i.e., spell them out). These rules apply across all academic disciplines that utilize APA style.

Here are the key instances where you should always spell out numbers:

• Numbers at the beginning of a sentence: This is a hard and fast rule. If a number starts a sentence, it must be written out. For example, instead of writing “10 participants were interviewed,” you would write, “Ten participants were interviewed.” This rule helps maintain a smooth reading flow.
• Common fractions: Fractions, such as “one-half” or “two-thirds,” should be spelled out.
• Numbers less than ten (excluding specific cases, which we’ll cover next): In most general writing, numbers one through nine are typically spelled out. For instance, write “five cats” instead of “5 cats.”

2. When to Use Numerals: The Exceptions to the Rule

While the above guidelines provide a solid foundation, there are several important exceptions where you should use numerals (digits) instead of spelling out the number, even if it’s less than ten. Understanding these exceptions is crucial for APA compliance.

Here’s when you should use numerals:

• Numbers in abstract or summary: In the abstract of your paper or a summary of your findings, you should follow the same rules as the main text. However, some journals may have specific formatting requirements for abstracts, so always consult the journal’s guidelines.
• Numbers representing time, dates, ages, scores, or points on a scale: For example, “The experiment lasted 3 hours,” or “The participants were between 18 and 25 years old.” Always use numerals for these types of data.
• Numbers that represent mathematical or statistical functions, ratios, and percentages: If you’re presenting statistical analyses, always use numerals. For example, write “The correlation was r = .75” or “25% of the sample…”
• Numbers immediately preceding units of measurement: Always use numerals when a number is directly associated with a unit of measurement. Examples include “3 cm,” “5 ml,” or “10 kg.”
• Numbers that are part of a series: If you have a series of numbers, even if they are under ten, and one of them needs to be written as a numeral, then use numerals for all numbers in the series. Example: “There were 2 cats, 7 dogs, and 12 hamsters.”

3. Large Numbers: The Tricky Territory

Dealing with large numbers can be particularly tricky. While the general rule is to spell out numbers under ten, the size of the number dictates the approach.

• Numbers over ten (and not starting a sentence): Use numerals. For example, write “15 participants” or “250 students.”
• Mixing Numerals and Words for Large Numbers: If you need to write a very large number, you can combine numerals and words to improve readability. For example, write “3.5 million” instead of writing out the entire number. This approach is particularly useful when presenting data in tables or figures.

4. Consistency is Key: Maintaining Clarity in Your Writing

Consistency is paramount throughout your document. Once you establish a rule for a particular type of number, adhere to it consistently throughout the entire manuscript. This applies not only to the main text but also to tables, figures, and appendices. Inconsistency can confuse the reader and undermine the credibility of your work.

5. Numbers in Tables and Figures: Special Considerations

Tables and figures often present numerical data, requiring a slightly different approach to formatting. The primary goal is to maximize clarity and readability.

• Use numerals for all numbers within tables and figures: This is standard practice to ensure the data is presented clearly and concisely.
• Consider the scale and context: If you are presenting very large numbers in a table, you may consider using abbreviations (e.g., “millions”) to conserve space and maintain readability.
• Provide clear labels and headings: Always clearly label your tables and figures, providing informative headings and axis labels to help the reader understand the data.

6. Ordinal Numbers: First, Second, Third…

Ordinal numbers (first, second, third, etc.) are often spelled out. However, there are exceptions.

• Generally, spell out ordinal numbers: For example, write “the first chapter” or “the second experiment.”
• Use numerals for dates: Always use numerals for dates, such as “April 3, 2024.”

7. Decimal Numbers: Precision Matters

Decimal numbers are crucial in scientific writing. Ensure you follow these guidelines:

• Use numerals for all decimal numbers: Write “0.25” not “zero point twenty-five.”
• Be consistent with the number of decimal places: The number of decimal places you use should be consistent throughout your paper, reflecting the precision of your measurements.

8. Numbers and Statistical Significance: P-Values

P-values are a critical aspect of statistical reporting. Proper formatting is essential.

• Always use numerals for p-values: For example, write “p < .05.”
• Be consistent with the number of decimal places: Report p-values to the appropriate number of decimal places, typically two or three.

9. Common Mistakes to Avoid

Several common mistakes can lead to errors in APA style number formatting. Being aware of these errors can help prevent them.

• Inconsistent use of numerals and words: This is a frequent error. Always review your work for consistency.
• Incorrectly spelling out numbers at the beginning of a sentence: Always double-check the first word of each sentence.
• Ignoring the rules for units of measurement: Always use numerals with units of measurement.
• Failing to follow journal-specific guidelines: Always consult the specific guidelines of the journal to which you are submitting your work.

10. Review and Proofreading: The Final Step

Thoroughly review and proofread your manuscript to ensure all numbers are formatted correctly. This is a crucial step to avoid errors and maintain the credibility of your work. It’s often helpful to read your manuscript aloud or have a colleague review it. Pay close attention to the consistency of your formatting.

FAQs

What if I’m unsure whether to use a numeral or spell out a number?

When in doubt, it’s generally better to err on the side of clarity. If the meaning of the sentence is clearer with numerals, use them. If the number is part of a series, use numerals across the board.

Does the APA style change based on the field of study?

While the core principles of APA style remain consistent across disciplines, specific journals or professors might have minor variations. Always consult the specific guidelines provided by your instructor or the target journal.

Are there any exceptions to the “numbers at the beginning of a sentence” rule?

No, there are no exceptions. If a number begins a sentence, you must spell it out.

How do I handle numbers when citing sources?

When citing specific page numbers, volume numbers, or issue numbers, use numerals. For example, (Smith, 2023, p. 15).

What resources can I use for further clarification?

Consult the Publication Manual of the American Psychological Association (7th edition). This is the definitive guide to APA style. You can also consult reputable online resources and style guides.

Conclusion

Mastering the rules for writing out numbers in APA style is essential for producing clear, accurate, and professional academic writing. By understanding the fundamental principles, the exceptions, and the importance of consistency, you can confidently navigate the complexities of numerical presentation. Remember to prioritize readability, clarity, and adherence to the APA guidelines. This guide should equip you to confidently format numbers in your APA-style papers, ensuring your work meets the standards of academic excellence.