@krellin, it is possible that you get away with 8 hours a day (after a few years of experience) assuming that you did actually teach... I have seen teachers do that... and they are crap. My wife is a teacher, two cousins and a grandfather are/were professors, and my mother in law was a teacher... and each of them put in more than a normal work day most days and definitely more than a normal work week every week and more than a normal work year every year. Incidentally, my wife, who was laid off this spring along with everyone else in the district with less than 8 years experience (thanks to budget cuts and resulting class size increases), my wife is right now working on lessons with a colleague. Yes - she isn't even employed and she's working - on the hope that it will help her prepare for a job that might or might not come next year. Later this summer she attends three different one week courses offered by the school district.
The work, for a half-way decent teacher, doesn't end on the last day of school nor does it end at 3PM... there is always more to do... If your day ended at 3 and your year ended on the last day of school, then shame on you. Oh - and as far as materials and equipment... well, she has paper rationed out to her. If she uses more than a ream a semester (which is a given that she will - obviously) then it is on her. She provides the pencils, if she wants something laminated she pays for it.
I was a student teacher this Spring and the science department I was in had a budget of $100 per teacher per year. This is science we're talking about... with equipment that breaks down, projector bulbs and such that go out, chemicals and biological specimens that get used... not to mention paper and toner. A kid loses a paper, and literally, the teacher would say "you'll need to get a copy from a friend". Several teachers had projector bulbs go out on them during the semester and literally they had to stop using the projector (this effects slide shows as well as videos and demonstration experiments). Granted, I live in California - which, though it boasts the sixth largest economy in the world also has the second lowest per student spending in the country (second only to Mississippi)... but things are hard all around. Education funding is based on property taxes and whatever the state gives you - both of which can vary significantly from year to year and decade to decade - and have been crap and getting worse for the last few years.
So - your lack of being able to see past your own lazy ass 8-hour-per day nose and your complete lack of knowledge of the economic situation in education in this country is hereby noted.