digit sum

Noun

 * 1)  The sum of all digits.
 * The digit sum of 517 is 5 + 1 + 7 = 13.
 * 1)  the number obtained when repeatedly applying above described operation until arriving at a single-digit number.
 * The digit sum of 517 is 4, since 5 + 1 + 7 = 13 and 1 + 3 = 4.
 * The digit sum of 517 is 4, since 5 + 1 + 7 = 13 and 1 + 3 = 4.

Usage notes
Those sources that hold to the first definition may refer to the second concept as the iterated digit sum, repeated digit sum or .

Translations

 * Danish: tværsum
 * German:, Ziffernsumme


 * Danish: tværsum, reduceret tværsum, itereret tværsum
 * German: einstellige Quersumme, iterierte Quersumme