Standard Mathematical Tables and Formulae

Information and errata for the 29th and 30th print editions and new electronic edition of this book.
http://smtf.mathtable.com/

Math2.Org

Formerly Dave's Math Tables. Mathematical tables on-line and downloadable.
http://www.math2.org/

Math Tables, Facts and Formulas

A mathematics reference collection of "K through 14" math tables, facts, definitions, formulas and explanations: compiled by Colby Community College Mathematics Department.
http://www.colbycc.org/www/math/math.htm

Geometry Formulas and Facts

An excerpt from the 30th Edition of the CRC Standard Mathematical Tables and Formulas, covering the area of Geometry (minus differential geometry), by Silvio Levy.
http://geom.math.uiuc.edu/docs/reference/CRC-formulas/

Glossary of Math Terms

Explains commonly used words specialized to this field. Includes examples and some graph illustrations.
http://www.dpi.state.wi.us/dpi/standards/mathglos.html

On-Line Encyclopedia of Integer Sequences

Identify a sequence by entering few terms in the sequence. Additional information includes examples, formulas, and related links.
http://www.research.att.com/~njas/sequences/

PlanetMath

A collaborative encyclopaedia with entries contributed under the GNU Free Documentation License.
http://planetmath.org/

Digital Library of Mathematical Functions

This mockup gives an idea of the current ideas about the design and organization of the new Digital Library; these ideas are, of course, subject to change. Content only is only available in a few places.
http://dlmf.nist.gov/

Platonic Realms

Online resource for the mathematics community: links library, bookstore, quotes, and online articles.
http://www.mathacademy.com/pr/index.asp

Math Assistance

Lists rules and formulas for a number of mathematical subjects, such as plotting graphics, functions, factoring, derivatives, integrals, matrices, vectors, and numerical analysis. In English, French and Turkish languages.
http://www.ercangurvit.com/

Summation Formulae

For polynomials of degrees up to 50, generated using the Euler-Maclaurin method.
http://polysum.tripod.com/

Quick Reference Pages

Free reference covering many topics, by Tim Martin.
http://www.asymptotic.co.uk/reference/

Mathematical Atlas

A topical guide to modern mathematics that explains the subdisciplines. Includes graphics that represent their relative size and relationship.
http://www.math.niu.edu/~rusin/known-math/welcome.html

Numbers and Numerical Prefixes

Tables for Greek and Latin number values alone and as a part of other words.
http://phrontistery.50megs.com/numbers.html

F2 - Math Formula Finder

Produces equations that match the name of the formula from a list. Can add onto the selection. Uses MathML coding.
http://f2.moris.org/

Wikipedia: Mathematics Section

Free encyclopedia. Cover number systems, different math fields, foundations, history, applications, and famous problems.
http://en.wikipedia.org/wiki/Mathematics/

Wolfram: Mathematical Functions

Includes advanced formulas and visualizations of various equation, such as elliptical curves.
http://functions.wolfram.com/

The Math Reference Project

An electronic archive of articles by Karl Dahlke on topics ranging from high school geometry up to graduate level topology.
http://www.mathreference.com/

The Abacus

Articles on the history, techniques, and construction of the abacus, with interactive Java Applet.
http://werwolf.ee.ryerson.ca:8080/~elf/abacus/

Mathematics Resources

This site comprises a large number of links to matheamtical resources, dedicated to various topics.
http://www.educationindex.com/math/