Web Hosting Talk : Other Forums : Computers and Peripherals : Windows calculator vs Excel

[bear]

Here's an odd one, and I think shows calc.exe is faulty and not to be trusted.
Take two values:
2829.00 and 108.125%
Divide the first by the second in both programs.
Excel gives 2616.416 [=A2/B2%]
Calc gives 3058.85625

Checking the calculation shows the number calc is returning is actually the first value multiplied instead of divided by the percentage. Deliberately choosing either divide or multiply in calc shows exactly the same result on two different systems here.

Still relying on calc to manage your figures?

[ThatScriptGuy]

Calc gave me 2616.416
Kevin

(2829.00/1.08125)

[bear]

Hmm...if I leave off the % at the end, the number is still wrong. It gives 26.164....
How did you arrive at using that value: 1.08125?

Math is obviously not my strong point, and this is puzzling me.

[ThatScriptGuy]

108.125% is equivalent to 1.08125

To get from a percent to a number, you simply move the decimal point two places to the left. (math is my strong point)
Therefore, 108.125 (move decimal two places left) is equal to 1.08125. So then, 2829.00/1.08125 = 2616.416
Kevin

[Techno]

How to use the % sign on a calculator:
http://www.staff.vu.edu.au/mcaonline...lculators.html

[bear]

Ah...coming back to me now, thanks kvnband.
Wonder why calc was choking on it being expressed the other way?

[SniperDevil]

Originally Posted by kvnband

(math is my strong point)

Not to detract from your innate abilities, but it doesn't exactly take a math genius to understand what a percentage means and, therefore, to be able to convert it to a decimal.

[ThatScriptGuy]

I was just throwing it out there for anyone who wishes to use that ever so helpful information. I'm a math major, so I do believe I could be of some assistance when someone is needing math help

[Koopa]

You can't beat an electronic calculator, for those important sums

[bear]

Originally Posted by Koopa

You can't beat an electronic calculator, for those important sums

My computer uses electricity....
It's the operator that lacks certain abilities...

[JayC]

It's just the algebraic logic that calc uses -- as do a lot of other simple calculators.

When you enter 2829.00 / 108.125 % you are asking for 108.125% of 2829. That division sign hasn't done anything yet, because the calculator is still awaiting the end of the equation. If you press equal after that, you'll get to the end of what's anticipated by that approach: 2829.00 divided by 108.125% of 2829.00.

That might not seem entirely useful, but the approach is aimed at a kind of calculation that is often done on simple calculators: adding percentages.

For example by entering 2829 + 8 % = you'll get 8% of 2829 added to that original 2829. That's a common type of calculation (adding a tip, or tax) for which a simple calculator might be used.

So it's not an error at all, it's just one of several approaches to data entry logic that might be used by a calculator.

[bear]

So, even though I entered it as divide by nnn%, it determines that what I really wanted was to multiply by that amount based on the % at the end? Kind if flawed logic, I feel, since if I wanted to multiply, I'd have used *. No idea that calc would "help" me in this way.
Defeated by a simple calc program....a misspent youth is finally haunting me...

[JayC]

Originally Posted by bear

So, even though I entered it as divide by nnn%,

It would have divided, but it would have divided the first number by nnn% [i]of the first number[/], not just by nnn%.

Maybe it is flawed logic, unless it's what you want to do.