MATH FEST 2015
17 proofs that 1=2 (But Proofs #6,#7,#9 need Jim Tanton and you can't download him!)
100 Problems involving the Number 100
Primer on Abott & Costello Numbers
The Brain puzzle 
spinout 
and the GRAY CODE
(The secret to many of these 70s puzzles is that at each step there are only two choices and one of them you just did!)
JOE GALLIAN's 75 YEARS of CONTESTS . (BIG FILE WITH VIDEOS)
JOE GALLIAN's 75 YEARS of CONTESTS (PDF VERSION)