A YouTube channel of maths instructional videos, mostly aimed at school level, organised into dozens of topic playlists such as "Financial Math", "Differentiation Applications", "Ratios and Proportions", and "Systems of Equations and Inequalities". The videos can also be browsed through a database
Video and Audio Lectures in Maths for Economists
More than sixty short films explaining mathematical concepts by putting them in a real-world context, hosted by Ken Heather of the University of Portsmouth. Each video combines a live-action explanation of the idea followed by a numerical example which is worked through on-screen. Each film can be downloaded in low resolution or high-resolution Windows Media format, or viewed in YouTube. The animations can be viewed separately as Flash files that play in a web browser. The five categories are 1) Mathematical review, 2) Linear equations, 3) Mathematics of finance and growth, 4) Linear programming, and 5) Differentiation and integration.
Many dozens of short tutorial videos on mathematical topics, especially calculus and algebra. Each lasts a few minutes and gives audio narration while you see the instructor's hand writing. The videos can be watched for free on YouTube.