343 in Words

How do you write 343 in words?

The number 343 is written three hundred forty-three in words. As an ordinal it is three hundred forty-third, and on a check you would write Three hundred forty-three and 00/100.

Last updated 24 August 2026

Other ways to write it

Cardinalthree hundred forty-three
Ordinalthree hundred forty-third
Currencythree hundred forty-three dollars
Check formatThree hundred forty-three and 00/100

How 343 is written

343 is the sum of its place values, 300 + 40 + 3, and is written three hundred forty-three.

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

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

Its Roman numeral CCCXLIII 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 343

  • 343 is an odd number.
  • It is not a prime number.
  • Digit sum: 10.
  • Roman numerals: CCCXLIII.
  • Binary: 101010111.
  • Hexadecimal: 157.
Place-value breakdown of 343
DigitPlace
3hundreds
4tens
3ones

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Frequently asked questions

How do you write 343 in words?

343 in words is "three hundred forty-three".

How do you spell 343?

343 is spelled "three hundred forty-three".

How do you write 343 on a check?

On a check, write "Three hundred forty-three and 00/100".