Calculus

Calculus 1A: Differentiation
Calculus 1B: Integration
Calculus 1C: Coordinate Systems & Infinite Series

Discrete Math

Mathematics for Computer Science
Mathematics for Computer Science 2

Linear Algebra

Linear Algebra - MIT
http://immersivemath.com

Probability and Statistics

Introduction to Probability and Statistics
seeing-theory
Statistical Thinking and Data Analysis

Optimization

Optimization Methods