Lesson #2
Here is a review of compound interest.
Introduction to compound interest and e: Compounding interest multiple times a year.
Compound Interest and e (part 2): Compounding 100% annual interest continuously over a year converges to e (2.71...)
Lesson #4
Solving Logarithmic Equations: Solving Logarithmic Equations
Lesson #5
Richter Scale: The basics of the logarithmic Richter and Moment Magnitude Scales to measure earthquakes