Local math circles

• San Jose math circle
• Berkeley math circle
• San Francisco math circle

Local math activities

• Bay Area Math Adventures
• Bay Area Math Olympiad

Math resources on the web

• Frank Potter's math gems
• Interactive math miscellany and puzzles
• Mathematics sites for educators
• Fun math facts
• Mathematical software resources
• Problems of the week
• Art of problem solving
• Mathworld (Wolfram)
• Math forum
• Maths online
• S.O.S. Math
• American mathematics competitions
• Factorization applet
• Arbitrary precision calculator