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Basic Math/Division With & Without Units

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Question
Hello:

Would there be a reason to divide a number without units by another number with units?  Here is an example:

35 divided by $5.00 or 35/$5.00

The answer cannot have units ($) because $5 X 7 does not equal 35 but instead $35.00.

$35.00 divided by 5 or ($35.00/5) and $35 divided by $5.00 or  ($35.00/$5.00) make more sense.

I thank you for your reply.

Answer
Yes, but I say that in practice we can attach units to just about anything.

Some examples:
1. $35 divided by 5, we can think of $35 being split 5 ways, say among 5 people
.  Thus, $35/5 ppl = $7 per person.

2. 35 divided by $5, we can think of $5 buys us 35 of something, say 35 eggs.
.  Thus, 35 eggs/$5 = 7 eggs/$ or 7 eggs per dollar, i.e. $1 dollar buys us 7 eggs.

See?

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Abe Mantell

Expertise

Hello, I am a college professor of mathematics and regularly teach all levels from elementary mathematics through differential equations, and would be happy to assist anyone with such questions!

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Over 15 years teaching at the college level.

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NCTM, NYSMATYC, AMATYC, MAA, NYSUT, AFT.

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B.S. in Mathematics from Rensselaer Polytechnic Institute
M.S. (and A.B.D.) in Applied Mathematics from SUNY @ Stony Brook

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