Date: Feb 2, 2005 6:09 PM
Author: Bob
Subject: Re: volume of a cylinder

On Tue, 01 Feb 2005 04:33:49 GMT, kalanamak <>

>Bob wrote:

>> Why not drop back one dimension. The same idea holds for perimeter vs
>> area, and it is easier to see. Take a loop of string (constant
>> perimeter), and show that it bounds different areas depending on
>> shape.

>Yes, but I'm still with the quandry over what to say to "why". If the
>answer is "because that's the way it is, honey", fine, but I was
>wondering if I was missing an answer to why a kid could understand.
>Perhaps I'm the kid here, and someone needs to reassure me its just the
>way it is, nothing more to be said.

I think you said these were five year olds. Their view of "why" is
different from yours. Seeing is the why. If they want more, show how
the amount of "inside" differs.

Another demo... Take a balloon or plastic bag or such. It will hold
some water/sand. But you can also squeeze _all_ the insides out.
Insides (volume) and outsides (surface area) are different things.

It's great that you are trying to anticipate their questions and
concerns. But they will surprise you, with ones you had not thought


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