As an IELTS instructor with over 20 years of experience, I often get asked by my students about the “dos and don’ts” of IELTS Writing, and one common query is about writing numbers. Specifically, “Do you write out numbers in words for IELTS Writing?” The answer, like many things in English, is: it depends. Let’s clarify when to use numerals and when to spell out numbers in your IELTS Writing exam.

Understanding the Rules of Numbers in IELTS Writing

While there’s no hard and fast rule stating you must always write out numbers in words, the way you present numbers can impact the clarity and formality of your writing, ultimately affecting your score.

Here’s a breakdown to guide you:

When to Spell Out Numbers:

1. Numbers at the Beginning of a Sentence: It’s generally best practice to spell out numbers when they appear at the start of a sentence.

   • Example: Instead of “100 students participated,” write “One hundred students participated.”

2. Small Numbers: For numbers ten and under, consider spelling them out, especially in less formal writing tasks (like IELTS Writing Task 1 describing a process).

   • Example: “The process involves four distinct stages.”

3. Rounded Numbers or Approximations: When you’re not being precise, it often sounds more natural to use words.

   • Example: “Approximately two-thirds of the respondents agreed.”

When to Use Numerals:

1. Large Numbers: For numbers larger than ten, numerals are often clearer and more concise.

   • Example: “The population reached 15 million in 2022.”

2. Dates, Times, Percentages, and Statistics: Using numerals in these contexts is standard practice.

   • Example: “The survey was conducted in 2023, with 75% of respondents aged between 18 and 25.”

3. Units of Measurement: Stick to numerals for measurements.

   • Example: “The experiment required 250 ml of water.”

IELTS Writing Task 1 Graph Example

Examples from IELTS Writing:

• Task 1 (Graph Description): “The number of tourists visiting the country increased dramatically from 2 million in 2005 to 8 million in 2015.”

• Task 2 (Essay): “One significant argument against this policy is…”

Tips for Success:

• Be Consistent: Choose a style and stick to it throughout your writing. Don’t switch back and forth between numerals and words unnecessarily.
• Focus on Clarity: Your primary goal is to communicate your ideas effectively. Select the format that makes your writing easiest to understand.
• Read Widely: Familiarize yourself with how numbers are used in different contexts by reading English texts regularly. This will help you develop a natural feel for when to spell out numbers and when to use numerals.

Remember, the IELTS Writing exam assesses your ability to present information clearly, accurately, and appropriately. By understanding these guidelines, you can ensure your use of numbers enhances, rather than detracts from, your writing.