List of sites with puzzles/problems

Los Alamos Mega-Math project Los Alamos G
Naor's puzzlerMoni Naor's collection of Math puzzles Weizmann Inst. X
The MathSoft Puzzle Page Cambridge, MA, USAR
Physics Quiz GermanyPG
ChallengePhysics Challenges Duke University, USAPG
NRICH math online club Cambridge University, EnglandG
BrainTeasers by Quantum Journal Nat.Sc. Teachers Assoc. (US)G
Physics Prob. Collection by A. Melikidze Princeton University, NJ, USA R
"Ponder this" - math puzzles IBM (T.J. Watson) Res.Labs, NY,USA R
"Physics of the outdoors" by S.M. van Roode The NetherlandsR
OrtvayYearly Physics Competition HungaryR

The rating refers to the difficulty (prerequisite knowledge required) to solve a typical problem in that site. It is vaguely defined as follows: G=high-school; PG=high-school/undergraduate students; R=university students; X=graduate student/researcher.

If you know an address of an additional site with physics/math problems or puzzles, please mail the address to

[Please, ask your webmaster or equivalent computer-wiz to include a reference (link) to our page ( in the appropriate web page of your organization.]