puts Math.log(1) # => 0.0
puts Math.log(Math::E) # => 1.0
puts Math.log(10) # => 2.30258509299405
puts Math::E ** Math.log(25) # => 25.0
puts Math.log10(1) # => 0.0
puts Math.log10(10) # => 1.0
puts Math.log10(10.1) # => 1.00432137378264
puts Math.log10(1000) # => 3.0
puts 10 ** Math.log10(25) # => 25.0