When I teach functions to 6-8th graders in a math class I often use the example of a soda/vending machine. I first saw this worked through in the CPM math textbooks, which have a very conversational tone and strong constructivist leanings. This has the benefit also having simple examples that explain the difference between functions and non functions (consistent sodas/output form a particular button/input), injective, and surjective functions. And I made a neat poster of it, which is probably more important for the 12 year old then it is for your students.
Andrew Carle MS Technology The Hamlin School _______________________________________________ Edu-sig mailing list [EMAIL PROTECTED] http://mail.python.org/mailman/listinfo/edu-sig
