What are Natural Logs?
Some business calculators have natural logarithm functions instead of base-10 logarithms.
Many scientific calculators have both.
Natural logarithms use the number (e = 2.7183...) as their base instead of the number 10.
Natural logs usually use the symbol Ln instead of Log.
Natural antilogs may be represented by symbols such as: InvLn, Ln-1 ex , or exp.