# 10.4.3 Calculator Wrong!

Discussion in 'macOS' started by alexprice, Nov 3, 2005.

1. ### alexprice macrumors 6502a

Joined:
Jan 8, 2005
#1
Goto Calculator and switch to Scientific mode,

Do...

62 + 40% =

What is the result?

also

What version of 10.4 are you using?

In 10.4.3 I get 62.4

2. ### wordmunger macrumors 603

Joined:
Sep 3, 2003
Location:
North Carolina
#2
I'm using Panther and I get 86.8. But technically 40% = .4, so your answer is "right" as well. It depends on the order of operations.

3. ### alexprice thread starter macrumors 6502a

Joined:
Jan 8, 2005
#3
I dont understand?

40% of 62 = 62.4?

4. ### wordmunger macrumors 603

Joined:
Sep 3, 2003
Location:
North Carolina
#4
What your calculator is doing is this:

62 + (40%)
= 62 + 0.4
= 62.4

What my calculator is doing is this:

62 + (40% * 62)
= 62 + (0.4 * 62)
= 62 + 24.8
= 86.8

5. ### alexprice thread starter macrumors 6502a

Joined:
Jan 8, 2005
#5
Unfortunatly Maths wasn't a subject I did well on, thanks for the answer tho.

How should I do it?

Joined:
Jul 19, 2005
7. ### andiwm2003 macrumors 601

Joined:
Mar 29, 2004
Location:
Boston, MA
#7

mathematically 40% equals 0.4 . just check in EXCEL spreadsheets.

or 40% of 62 equals 62 times 0.4

what happened here is that in panther they followed the convention that the 40% is 40% of 62.

in tiger they followed the convention that excel is using.

both are correct.

8. ### SilentPanda Moderator emeritus

Joined:
Oct 8, 2002
Location:
The Bamboo Forest
#8
62 * 40%
+62

Probably... I'm not at my Mac. But it sounds like you need to get 40% of 62 then add the 62.

Or.... since you know 40% = .4 you could just do 62 * 1.4

9. ### alexprice thread starter macrumors 6502a

Joined:
Jan 8, 2005
#9
I think I understand, I thought it might be a bug as 10.4.2 doesn't do it.

Thanks for the response.

10. ### alexprice thread starter macrumors 6502a

Joined:
Jan 8, 2005
#10
I'm still a bit confused, I choose +40% of the last number (62), not 1.

Sorry if I'm starting to sound dumb, I'm just a little confused.

Thanks again.

11. ### ElectricSheep macrumors 6502

Joined:
Feb 18, 2004
Location:
Wilmington, DE
#11
I don't see where there would be confusion. I think to implicitly compute 60 + 0.4*60 when you type 60 + 40% would create more confusion and is not a good way to build a calculator.

12. ### gco212 macrumors 6502

Joined:
Jul 21, 2004
#12
You're not saying +40% of the last number. You're saying +40%. Percentages are just another way of writing decimals. You move the decimal 2 spots to the right, and you change from a decimal to a percentage. If you wanted to say +40% of the last number, you want to write 62 + (.4*62).

13. ### Abstract macrumors Penryn

Joined:
Dec 27, 2002
Location:
Location Location Location
#13
You can't even use a calculator?

How does 62 + 40% = 62 + (40% of 62)?? In no way does typing in "40%" into your calculator imply that it's 40% of 62 (ie: 62 * 0.40).

Your way is confusing, and wrong. 62 *1.4 is what people do.

14. ### MarkCollette macrumors 68000

Joined:
Mar 6, 2003
Location:
#14
If you type:

60 + 40%​

that makes no sense from a mathematical perspective. 40% of what?

Ok, so you expect it to be smart and know that it's:

60 + 40% of whatever came before​

So then, what should this do?

25 + 60 + 40%​

Should it be:

(25 + 60) + 40% of whatever came before ==> 119​

Or be:

25 + (60 + 40% of whatever came before) ==> 109​

For reference, what I would do, mathematically, is:

60 * 140%​

Joined:
Mar 24, 2003
Location:
California
16. ### mwpeters8182 macrumors 6502

Joined:
Apr 16, 2003
Location:
Boston, MA
#16
How many "the OS X calculator is wrong!!!" threads are there going to be. It works fine, I've never had an issue with it.

17. ### bluebomberman macrumors 6502a

Joined:
Jan 9, 2005
Location:
Queens, NYC
#17
You know you're bad at math when you don't know enough math to use the calculator properly...

18. ### ohcrap macrumors 6502a

Joined:
Aug 12, 2005
#18
This calculator "problem" has already been mentioned a few times, and it's not something anyone who knows anything about math should have a problem with.

It's not that difficult.

Joined:
Apr 21, 2003
Location:
washington dc
#19
was just about to bring this up...

good grief... if apple can write an ENTIRE OPERATING SYSTEM, then i have faith that their calculator works... save for human error

20. ### alexprice thread starter macrumors 6502a

Joined:
Jan 8, 2005
#20
I fully admit that maths isn't a subject I'm good with, the reason I thought it was wrong was because it didn't do it with 10.4.2.

Thanks for the replys, I do understand now.

The whole point in me using the calculator was that I wasn't very good with maths.

Alex

21. ### alexprice thread starter macrumors 6502a

Joined:
Jan 8, 2005
#21

LOL!!!!

I feel like the bunny.

22. ### BrandonSi macrumors regular

Joined:
Oct 13, 2005
Location:
Chicago, IL
#22
I want the pancake.

23. ### jeremy.king macrumors 603

Joined:
Jul 23, 2002
Location:
Fuquay Varina, NC
#23
The OP has a point so don't bash the guy for NOT doing anything wrong. Usually, on a REAL calculator, when you hit a number followed by the % key, it will take that percentage of whatever the result was on the display before entering in the percentage number. The point is that the Apple calculator in Tiger isn't behaving like a real calculator. Even the windows calculator will give the correct result.

If you don't believe me, try it on a good ol solar powered beauty...

62 + 40 % = 86.8

With that said, alexprice - please brush up on your math - knowing the way percentage's translate to decimals is a good skill...It will prevent you from being taken advantage of when you go to finance something or calculating a discount or a tip...

24. ### jeremy.king macrumors 603

Joined:
Jul 23, 2002
Location:
Fuquay Varina, NC
#24
And the whole reason most people aren't good with Math is the calculator...

I digress...I love the look I get when I give more money than I need to a cashier so I wont get more bills and coins back...For example. If I buy something and the total is 5.78 and I give the cashier 11.03, they always look at me as to why I am giving the extra 1.03. My response is always "just trust me."

25. ### simie macrumors 6502a

Joined:
Aug 26, 2004
Location:
Sitting
#25

10.4.3 calculator does in fact work like Excel.

Try using this formula to find 40% of 62

62*40/100 =24.8

or

62*0.4=24.8