Math Forum http://mathforum.org/kb List of forum topics en Calcudoku number puzzles for secondary school students http://mathforum.org/kb/thread.jspa?messageID=7855565&tstart=0#7855565
Last year I created a site with Calcudoku number puzzles,
aimed at secondary school students:

 Jul 31, 2012 11:12:57 AM Jul 31, 2012 11:12:57 AM pmin00 0