Q&A #7009

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From: Loyd

To: Teacher2Teacher Public Discussion
Date: 2001122313:34:34
Subject: Volume

It is not often that you find someone who is aware that if you double
the diameter of a sphere (or apple, plum, cherry) you will get 8 times
as much.  When it comes to hot dogs, where the length remains the
same, but the diameter gets cut in half, then the factor will be 1/4
as much.  In the sphere we double 3 dimensions whereas in a cylinder,
if we hold the length constant, we only double two dimensions.  

Students could bring in a collection of apples of various sizes and
have the students weigh and measure the diameters using s tool or
measure the circumference and calculate the diameter.  

When I was a kid, I had the opportunity to pick plums, apples,
cherries and currents.  It doesn't take long to pick a bucket of
apples.  You can pick a bucket of plums in about 8 times as long as it
takes for apples.  For Cherries, it takes about 64 times as long to
pick a bucket of them as it does for apples. Imagine how long it takes
to pick a bucket of currents which are about half the size of

When you by cantaloupe by the piece, you will get lot more by picking
out the biggest in the store or patch.  

If you have noticed, manufacturers have reduced the diameter of lots
of items in the past 30 or 40 years.  They learned their math well.

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