High Quality Content by WIKIPEDIA articles! The multiplicative digital root of a positive integer n is found by multiplying the digits of n together, then repeating this operation until only a single digit remains. This single digit number is called the multiplicative digital root of n. Multiplicative digital roots obviously depend upon the base in which n is written. If the term is used without qualification, it is assumed that n is written in base 10. Multiplicative digitial roots are the multiplicative equivalent of digital roots.