Rational pricing of many financial products rely on mathematical modeling of random phenomena (e.g. the time evolution of a stock price). In this talk I will discuss the fundamental ideas of random walks, Brownian motion, and Ito Calculus, with applications actuarial science and finance. This presentation also serves as a nice introduction to what students can expect in part of Math 313 - Financial Mathematics for Actuaries (a.k.a. "Financial Derivative Pricing) - which is offered in Spring 2024.