AHU Resource Guides: Math & Numbers: Start Here

Math Test Preparation

Here are some "free" scientific" calculators mentioned on Free Technology for Teachers by Richard Byrne.

Check out these online websites for math assistance.

Academic Earth -- Mathematics
Online videos from higher ed professors. Goal is to share high quality educational content for free.
Brightstorm -- Math Help
Brightstorm is a provider of online study materials for mathematics (basic math and algebra) as well as ACT and SAT preparation. The ACT and SAT preparation materials are not free, but the mathematics tutorials are free.
Khan Academy
Resources/videos to learn math and other subjects.
Math Basics
GCF Learning.org
Math is Fun
Fun material about math (K - 12, but also good for the general person who "fears" math).
Math TV
Math TV provides an extensive collection of high quality mathematics tutorials. Math TV's video lessons cover basic mathematics and Algebra.
Math with Mr. V
Math Class With Mr. V features seven playlists made by a mathematics teacher teaching lessons on basic mathematics, geometry, and algebra.
WatchKnowLearn.org
Tutorials /videos that include algebra, pre-calculus and calculus.
Yay Math
YayMath.org is the first site ever to have math videos filmed in a LIVE classroom. We are boldly redefining how people perform better in math.

These tools are mentioned quite a bit online by math experts.

Wolfram Alpha
This is a computational knowledge engine.
Wolfram|Alpha aims to bring expert-level knowledge and capabilities to the broadest possible range of people—spanning all professions and education levels.
10 amazing uses for Wolfram Alpha
Wolfram Math World
From Wolfram Research and nurtured by Eric Weisstein
Wolfram Functions