The digital root in math is the single-digit value obtained by continuously summing the digits of a number until only one digit remains.

How Digital Roots Work?

  • Start by adding the digits of a number.
  • If the result has more than one digit, repeat the process with the new sum.
  • Continue until a single-digit number is reached.
  • For example, for \(67392\): \(6 + 7 + 3 + 9 + 2 = 27\) then, \(2 + 7 = 9\). So, the digital root is \(9\).

Applications

  • Used to check arithmetic calculations, especially for addition, subtraction, and multiplication by confirming digital roots match expectations.
  • Helpful in divisibility tests, particularly for \(9\) (and sometimes for \(3\)).
Important!
The digital root of multiples of \(9\) is \(9\).