840 in Words

How do you write 840 in words?

The number 840 is written eight hundred forty in words. As an ordinal it is eight hundred fortieth, and on a check you would write Eight hundred forty and 00/100.

Last updated 24 August 2026

Other ways to write it

Cardinaleight hundred forty
Ordinaleight hundred fortieth
Currencyeight hundred forty dollars
Check formatEight hundred forty and 00/100

How 840 is written

840 is the sum of its place values, 800 + 40, and is written eight hundred forty.

Its ordinal form is eight hundred fortieth — only the final element takes the ordinal ending — and on a check the amount line reads "Eight hundred forty and 00/100", where 00/100 stands for zero cents.

British English inserts "and" before the last part, giving eight hundred and forty, where American English writes eight hundred forty without it.

Its Roman numeral DCCCXL uses subtractive notation: XL means 40, written as X before L instead of repeating X.

For house-style rules on spelling out numbers, see the Chicago Manual of Style.

Facts about 840

  • 840 is an even number.
  • It is not a prime number.
  • Digit sum: 12.
  • Roman numerals: DCCCXL.
  • Binary: 1101001000.
  • Hexadecimal: 348.
Place-value breakdown of 840
DigitPlace
8hundreds
4tens
0ones

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Frequently asked questions

How do you write 840 in words?

840 in words is "eight hundred forty".

How do you spell 840?

840 is spelled "eight hundred forty".

How do you write 840 on a check?

On a check, write "Eight hundred forty and 00/100".