That's easy to calculate. You don't need a calculator. And therefore, our goal is to convert this natural log into base ten log? And the way we do it is we have to remember from algebra what the base conversion formula is for logs. In other words, this is a formula that basically tells us we can convert any log of any base of any inside to the base of ten. So the way we do it is log of base X of Y is equal to log of base ten of y divided by log of base ten of X.