In article <1srgqlrcsg88f$.co8ageth5gmp$.dlg@[EMAIL PROTECTED]
>,
Brian M. Scott wrote:
> 80% of 15 is 0.8 * 15 = 12, so he got 12 of the 15
> true-false questions right. [...]
Changing subject: if I were asked why we multiply the percent by the
amount which we want to find a percent of, I would answer something like
the following.
By definition, 80% is 80 out of each 100. If we had 15 hundreds, then we
would have
80% of 15 hundreds = 80 + 80 + ... + 80 = 80 * 15 = 1200.
If we now divide this equation by 100, we get
0.8 * 15 = 12.
So we use the x/100 for x% and multiply by the given quantity because it
is the same thing as augmenting the given quatity in amounts of hundreds
so that we can extract x out of each hundred and add them as many times
as necessary to know the total that composes the x% we're interested in.
Thoughts?
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