Ed, and friends:
Let me suggest examples suggesting that one can multiply (or divide)
things of different units:
48 oranges / 24 students = 2 oranges/student.
[aside: If you don't choose the numbers carefully, you have problems:
49 oranges/24 students = food fight.
17 oranges/24 students = fruit salad.]
From the old St. Ives riddle:
7 wives x 7 sacks/wife = 49 sacks.
We add the sacks to each other, but need the number of wives merely to
keep track of how many times we should do it.: 7 sacks from Alice + 7
sacks from Bertha + 7 sacks from ....
It is easy to generalize from these to real numbers.
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Dr. David W. Steyert steyert_dw@mercer.edu
Department of Chemistry (912)-752-4173
Mercer University
Macon, GA 31207
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