Logic Puzzles
Try out these logic puzzles from mathisfun.com:
http://www.mathsisfun.com/puzzles/logic-puzzles-index.html
http://www.mathsisfun.com/puzzles/logic-puzzles-index.html
Sieve of Eratosthenes
Try to solve this sieve of eratosthenes from Mrs. Glosser's Math Goodies on mathgoodies.com:
http://www.mathgoodies.com/webquests/number_theory/PDF/unit3_wks2.pdf
http://www.mathgoodies.com/webquests/number_theory/PDF/unit3_wks2.pdf