Math, Human-Edited Directory, Users Friendly Web Portal

Directory Listing(s)

Coolmath.com
features puzzles, fractals, games, lessons, calculators, and more.
http://www.coolmath.com/

Eric Weisstein's World of Mathematics
comprehensive and interactive encyclopedia of mathematical equations, terms, derivations, and more, for students, educators, math enthusiasts, and researchers.
http://mathworld.wolfram.com/

Knot a Braid of Links
weekly selection of graphically interesting mathematics sites.
http://www.cms.math.ca/

Math Database
search through journals from 1931 to the present.
http://www.emis.de/

Math in Daily Life
explore how math can help you in your daily life, and look at the language of numbers through common situations, such as playing games or cooking.
http://www.learner.org/

Plus
Articles explaining the diverse applications of mathematics within physics, chemistry, biology, engineering, and economics, plus stories about new developments in mathematics and interviews with mathematicians.
http://plus.maths.org/

Probability Tutorials
online course on measure theory, lebesgue integration, and probability. Individual lessons appear in PDF format.
http://www.probability.net/