About the Digital Root
The digital root repeatedly adds the digits until one digit remains.
For positive integers, it can be obtained directly from the number modulo 9.
Calculate the digital root of a positive integer using repeated modulo-9 arithmetic.
The digital root repeatedly adds the digits until one digit remains.
For positive integers, it can be obtained directly from the number modulo 9.
| Positive Integer | 9875 |
| Digital Root | 2 |
| Remainder Modulo 9 | 2 |
9875 modulo 9 is 2, so the digital root is 2.
Try this example โIt is the single-digit value obtained by repeatedly summing the digits.
In base 10, powers of 10 leave remainder 1 modulo 9.
It is 9 for the positive-integer convention.