[Edu-sig] explaining functions [Possibly OT]

[Andrew Carle]

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