DaveC426913 said:
Of course it can be done.
Sure, it just seems much more complicated to me than doing the same calculations without the pizza-metaphor.
DaveC426913 said:
Why is that cheating? That's what you're supposed to do. (though it's not the best example)
Because, if you know to do that, you might as well simply explain how those rules work without using pizzas, as pizzas will only add additional complexity from that moment on. Don't get me wrong, if the pizza example teaches people to do that, I'm fine with it, but I also know a few people who can't do such calculations without resorting to pizza metaphors. If you think of all fractions as pizzas, a fraction times a fraction makes very little sense. (It's really not that uncommon, I think. My parents, for example, simply don't think of the fact that 3/5 = 3*(1/5) when trying to calculate something. Of course, I might simply be from a weird family.)
DaveC426913 said:
I didn't immediately assume that, actually. I was under the impression that the OP was trying to find a method to teach *other* people who were having difficulty with math. Although now that I reread it, both assumptions seem somewhat unfounded.
DaveC426913 said:
People are thinking rationally! Why would you claim this isn't rational?
Let me rephrase: when I gave extra lessons to people in high school, I sort of relied on the fact that they would be able to follow the logical processes used in math. Younger children still have to learn those processes, something I wouldn't like to teach. That's why I would make a bad teacher at an elementary school.