[X4U] Tiger's Calculator.app no longer does percentages?

[Neil]

on 11/27/05 1:49 AM, John Baltutis wrote:

> Really? 15%, by definition, is 15/100 = 0.15. See
> <http://www.mathleague.com/help/percent/percent.htm>,
> <http://www.math.com/school/subject1/lessons/S1U1L7GL.html>, and
> <http://www.purplemath.com/modules/percents.htm>.

You can quote all the URL's that you want, but it doesn't do you any good
unless you actually read them.

>From your first link:
> 5% of something = 5/100 of that thing

So, 5%=.05 only if "that thing" is 1.

>From your last link:

> Percentages refer to fractions of a whole

For some reason you assume that the whole is always equal to the number one.
Which means that a 15% tip would always be $0.15.  All I'm saying is that
you can't answer the question "What is 15%?" without knowing the "of what?"


You said:
> The original problem was the sum of two numbers:

No, this is why you are confused.  15% is not a number, it's a ratio.  You
don't know it's value until you apply the ratio to the operand.

>  28.05 + 15% = 28.2,
> which is mathematically correct.

That is only mathematically correct if you assume your operand is 1.  When
your dinner bill is 28.05 and you add a 15% tip, I hope you take 15% of the
28.05 and not 15% of one dollar.