Digital Root/Examples

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Examples of Digital Roots

$34716$ Base $10$

In conventional base $10$ notation, we have:

$\map {s_{10} } {34716} = 3 + 4 + 7 + 1 + 6 = 21$

and then:

$\map {s_{10} } {21} = 2 + 1 = 3$.

So the digital root of $34716$ (base $10$) is $3$.


$10010111101$ Base $2$

In binary notation, we have:

\(\ds \map {s_2} {10010111101_2}\) \(=\) \(\ds 1 + 0 + 0 + 1 + 0 + 1 + 1 + 1 + 1 + 0 + 1\) \(\ds = 7 = 111_2\)
\(\ds \map {s_2} {111_2}\) \(=\) \(\ds 1 + 1 + 1\) \(\ds = 3 = 11_2\)
\(\ds \map {s_2} {11_2}\) \(=\) \(\ds 1 + 1\) \(\ds = 2 = 10_2\)
\(\ds \map {s_2} {10_2}\) \(=\) \(\ds 1 + 0\) \(\ds = 1 = 1_2\)

It is pretty obvious that the digital root of any non-zero number in base $2$ is always $1$.