Rue 1: At the beginning of a sentence

Always spell numbers at the beginning of a sentence, irrespective of how small or large they are.

Examples:

Four people were in the car.

Seventy-four thousand spectators watched the football match.

This rule applies to ordinal numbers (first, second, etc.), and fractions (quarter, half, etc.).

For example:

Half of all people entitled to vote in the election did not vote.

Rule 2: In the middle of a sentence

Round numbers, ordinal numbers (first, second, third, etc.), and common fractions (half, quarter, third, two-thirds) that appear in the middle of a sentence should be written. Rules three to nine apply to other numbers.

Rule 3: Whole numbers

Subject to rule 1 above, whole numbers up to one hundred should be written out.

Example:

There are fifty musicians in the orchestra.

Rule 4: Decimal numbers

Decimal numbers should be written as figures irrespective of where they appear in the sentence.

Examples:

Only 33% of those entitled to vote in the election did so.

20% of the votes cast were for the Red Party.

Rule 5: Units of measurement

Spell out whole numbers used with a unit of measurement, such as distance, money, time, etc., but do not spell out decimal numbers.

Examples:

It is twenty miles from the service station.

Tickets to the concert are fifty dollars each.

The bus company increased the minimum cost of a single ticket to £2.50

Rule 6: Large non-round numbers

Use commas to separate the digits into thousands and hundreds.

Example: The stadium holds 74,500 spectators.

Rule 7: Very large numbers

When writing very large numbers that are not round, use a numeric figure followed by a spelled-out qualifier.

Example: Astronomers using the James Webb space telescope have discovered a galaxy that is 21.6 million light-years from Earth.

Rule 8: Two numbers in a row

When two numbers need to be placed consecutively, write out one of them and use digits for the other.

Examples:

Only the first three 10-year-olds will receive a prize.

Only the first 3 ten-year-olds will receive a prize.

Rule 9: Dates

Specific years should be written as numbers, but decades and centuries must be spelled out.

Example:

The Social Democratic Party was formed in 1981 but merged with the Liberal Party in the eighties to form the Liberal Democrats.

Rule 10: Numbers in titles or headings

Numbers in titles or headings are not spelled out.

Example:

10 Simple Rules for Writing Numbers

Conclusion

Following these ten simple rules will ensure your writing is consistent, accurate, and professional. Knowing when to spell out numbers or use numerals allows you to focus on creating engaging content.