1. What is Digital Root?

The digital root of a non-negative integer is the value obtained by an iterative process of summing digits until a single-digit number is achieved. It's also known as the repeated digital sum.

2. How Does the Calculator Work?

The calculator uses the digital root formula:

Where:

• \( n \) — Any positive integer
• \( dr \) — Resulting digital root (1-9)

Explanation: This formula provides a direct calculation method without needing to sum digits repeatedly.

3. Importance of Digital Root

Details: Digital roots are used in numerology, checksum calculations, and various mathematical puzzles. They can help detect errors in manual calculations.

4. Using the Calculator

Tips: Enter any positive integer to calculate its digital root. The calculator will return a value between 1 and 9.

5. Frequently Asked Questions (FAQ)

Q1: What's the digital root of 0?
A: By convention, the digital root of 0 is 0, though the calculator only accepts positive integers.

Q2: How is this different from modulo 9?
A: Digital root equals n mod 9, except when n is a multiple of 9 (then digital root is 9, not 0).

Q3: What are practical uses of digital roots?
A: Used in checksums (like ISBN numbers), numerology, and as a quick calculation check.

Q4: Can digital roots be calculated for decimals?
A: No, digital roots are only defined for integers.

Q5: Is there a digital root for negative numbers?
A: The concept is typically only applied to non-negative integers.