These worksheets provide practice with the quantitiative skills required for economics course work.
Statistics Quick Helps
Confidence Intervals and Hypothesis Tests
Other Useful Websites and Resources
MathTv.com contains videos offering help in Algebra, Trigonometry, Calculus, and much more.
Wolfram Alpha is a useful mathematics search engine from the makers of Mathematica.
Hippocampus.org has many useful tutorials for algebra, calculus, statistics, chemistry, physics, and biology.