Mac OS X calculator

[samanthas]

Ok so, how do you do a percentage? I can't believe the calculator doesn't have a percentage!

And also, if there another calculator that I can download somewhere? Widget or not.

 

[4409723]

Ok so, how do you do a percentage? I can't believe the calculator doesn't have a percentage!

And also, if there another calculator that I can download somewhere? Widget or not.

Open the program, go to view, select scientific.

 

[Thomas Harte]

In the menubar, select View->Scientific to enable a wider version of the calculation, with a percentage button. But I've never really understood the point of it - doesn't it just divide by 100?

 

[4409723]

In the menubar, select View->Scientific to enable a wider version of the calculation, with a percentage button. But I've never really understood the point of it - doesn't it just divide by 100?

Yeah, quite a pointless button, probably why they left it off.

 

[Doctor Q]

I find it annoying to have to use menu choices with a calculator. Luckily, Command-1 and Command-2 (and Command-3 for us programmers) are there to save the day.

 

[mrichmon]

Ok so, how do you do a percentage? I can't believe the calculator doesn't have a percentage!

Err...

How difficult is it to multiply by 0.60 to get 60%?
Or multiply by 0.0125 to get 1.25%?
Or multiply by 0.99 to get 99%?

Are you seeing a pattern here? Yes, it is the same pattern that you learnt in school. 🙂

 

[MacRumoron]

And also, if there another calculator that I can download somewhere? Widget or not.

http://www.pcalc.com/

its shareware

or you can check macupdate: http://macupdate.com/search.php?keywords=calculator&os=macosx&button.x=0&button.y=0

 

[Doctor Q]

Some calculators are smarter about percentages, letting you add 7% tax to the price of a $9.95 item by pressing

9 . 9 5 + 7 % =

which would make it a little more convenience than having to press

9 . 9 5 x 1 . 0 7 =

Even more so if you want to take 4.5% off a price, where

9 . 9 5 - 4 . 5 % =

would be easier than

9 . 9 5 x . 9 5 5 =

But Apple's calculator doesn't do % shortcuts like those.

Oddly, if you press 7 % you get 0.07000000000000001 but if you press 7 % = you get 0.07.

 

[Edot]

Some calculators are smarter about percentages, letting you add 7% tax to the price of a $9.95 item by pressingwhich would make it a little more convenience than having to pressEven more so if you want to take 4.5% off a price, wherewould be easier thanBut Apple's calculator doesn't do % shortcuts like those.

Oddly, if you press 7 % you get 0.07000000000000001 but if you press 7 % = you get 0.07.

Yeah whoever coded the Calculator app needs some serious help. It was full of errors a while ago, and they still haven't got their float conversions right.

 

[samanthas]

You don't have to be so rude. Geez. I just happen to like having a percentage button.

Thanks for those who helped me though.

 

[Mitthrawnuruodo]

Oddly, if you press 7 % you get 0.07000000000000001 but if you press 7 % = you get 0.07.

Edit: Forget my first respond... I'm stupid... 😱 😉

But even weirder... if you press 7 % 7 (or substitute the second 7 with any number) you get 0.0700000000000000

 

[jblock]

Yes, I keep waiting for the calculator to be updated to do simple percentage calculations. Is this even on Apple's radar?

 

[stridey]

Just use Google. It'll calculate any mathematical expression. 🙂

 

[Doctor Q]

Just use Google. It'll calculate any mathematical expression. 🙂

Google doesn't handle +% (sales tax) or -% (discount) either.

Instead of

9.95 + 7% = 10.6465

it computes it as

9.95 + 7% = 10.02

It's interesting that such a simple expression can have two different meanings.

Google and Calculator.app consider % in this case to mean "divided by 100", although Google also knows that 7% of 9.95 = 0.6965.

In the sales tax case, we humans consider % to be a verb taking an object, x percent of y, with a default object of the previously mentioned noun, so 9.95 + 7% means 9.95 + (7% of 9.95).

 

[mrichmon]

Google and Calculator.app consider % in this case to mean "divided by 100", although Google also knows that 7% of 9.95 = 0.6965.

In the sales tax case, we humans consider % to be a verb taking an object, x percent of y, with a default object of the previously mentioned noun, so 9.95 + 7% means 9.95 + (7% of 9.95).

The issue is that + 7% is not a valid mathematical expression. Or even a valid logical expression since there is no mention of what the 7% refers to. Is it the immeadiately preceeding value, the following value, or some other value?

For example, what does this mean?: 9.95 + 7% + 20

 

[Doctor Q]

The issue is that + 7% is not a valid mathematical expression. Or even a valid logical expression since there is no mention of what the 7% refers to. Is it the immeadiately preceeding value, the following value, or some other value?

For example, what does this mean?: 9.95 + 7% + 20

I think we are agreeing. It could be interpreted to mean either

9.95 + (7% of 9.95) + 20

or

9.95 + (7 / 100) + 20

Thinking of it another way, % should have two operands. When people omit the second operand, the "default" could be either the number mentioned before it, or it could be the number 1, since (7 % of 1) is (7 / 100).

Given the ambiguity, some calculators handle it one way and others another way.

 

[Mr. Mister]

I forget, does Mac OS X install with the calc app having all the other extensions, like Hex and Binary, or do you still have to move them around inside the Calculator.app package?

 

[mrichmon]

Thinking of it another way, % should have two operands. When people omit the second operand, the "default" could be either the number mentioned before it, or it could be the number 1, since (7 % of 1) is (7 / 100).

Given the ambiguity, some calculators handle it one way and others another way.

Yes, or it could mean 9.95 + (0.07 * 20), or 9.95 + (0.07 * arbitrary value) + 20.

Ultimately, % is not strictly an operator. Rather, it is a symbol denoting a concept. Since it is not a mathematical operator, various calculator implementations (hardware and software) implement it as a convenience function but do so in different ways.

I would argue that due to the ambiguity and thus the potential for errors in use, it is far better to ignore this button and handle percentage calculations manually as a multiplication. But then this is also because I believe that people should understand what is going on.

But yes, I think we are agreeing.

 

[Doctor Q]

I forget, does Mac OS X install with the calc app having all the other extensions, like Hex and Binary, or do you still have to move them around inside the Calculator.app package?

Press Command-3 in Calculator.app.