Change of Base of Logarithm/Base e to Base 10/Form 2

Theorem
Let $\log_{10} x$ be the common (base $10$) logarithm of $x$.

Let $\log_e x$ be the natural (base $e$) logarithm of $x$.

Then:
 * $\log_{10} x = \dfrac {\log_e x} {\log_e 10} = \dfrac {\log_e x} {2 \cdotp 30258 \, 50929 \, 94 \ldots}$

Proof
From Change of Base of Logarithm:
 * $\log_a x = \dfrac {\log_b x} {\log_b a}$

Substituting $a = e$ and $b = 10$ gives:
 * $\log_{10} x = \dfrac {\log_e x} {\log_e 10}$

The Natural Logarithm of 10:
 * $\log_{10} e = 2 \cdotp 30258 \, 50929 \, 94 \ldots$

can then be calculated or looked up.