How to read, write, and use large numbers in English.

How to Read Large Numbers

Reading large numbers involves grouping digits into sets of three (called periods) and naming each group based on its position (thousands, millions, billions, etc.).

Start from the right and separate the number into groups of three digits.
Read each group as a normal three-digit number.
Add the period name (thousand, million, billion) after each group, if needed.
Combine the parts together.

Examples using the number 1,234,567,890:

,234,567,890 → "one billion two hundred thirty-four million five hundred sixty-seven thousand eight hundred ninety"

Writing Large Numbers

Large numbers in English are written without commas or spaces in standard form, but commas are used to make them easier to read.

Use digits for numbers (e.g., 1,000,000).
Use commas to separate groups of three digits, starting from the right.
When writing in words, use "and" only in British English (e.g., one hundred and one); in American English, "and" is usually omitted.

Fill in the blank: The number 1,000,000 is written as 'one ________.'

hundred

million

thousand

billion

million

1,000,000 is called 'one million.' Thousand is 1,000; billion is 1,000,000,000.

Using Large Numbers in Context

Large numbers are used in various contexts like talking about population, money, distances, and more.

Use "thousand," "million," "billion," and "trillion" for large quantities.
Use "about," "approximately," or "around" to indicate estimates.
Be clear about units (dollars, people, kilometers, etc.).

Example sentences:

The city has a population of over two million people.
The company earned $3.5 billion last year.
The distance to the star is about four trillion kilometers.

How should you include units when using large numbers?

Units go at the beginning of the sentence.

Always mention the units (dollars, people, kilometers) for clarity.

Units are optional and usually understood.

Use units only with small numbers.

Always mention the units (dollars, people, kilometers) for clarity.

Specifying units (e.g., dollars, people, kilometers) is essential for clear communication, especially with large numbers.

Practice Examples

Here are some large numbers written in digits and words.

Digits	Words
,000	one thousand
,000	twenty-five thousand
,000,000	one million
,345,678	twelve million three hundred forty-five thousand six hundred seventy-eight
,000,000,000	one billion

You can create your own large numbers by combining these patterns.

Last updated: Wed Jun 18, 2025