Who was the ancient Greek mathematician known for his work with logarithms?

The ancient Greek mathematician known for his work with logarithms was John Napier. Napier was actually Scottish, not Greek, and lived from 1550 to 1617.

Napier published the first logarithm tables in 1614, in his book Mirifici Logarithmorum Canonis Descriptio. His method transformed difficult multiplications and divisions into simpler additions and subtractions, greatly helping astronomers, navigators, and surveyors perform calculations by hand.

Napier's original logarithms were not exactly the same as the natural logarithms commonly used today. Henry Briggs later worked with Napier to develop base-10 logarithms, which became especially popular. Napier also invented Napier's bones, a set of numbered rods used for multiplication.

A common mix-up is confusing Napier with ancient Greek mathematicians such as Euclid or Pythagoras. Those figures made major contributions to geometry and number theory, but logarithms were developed many centuries later.