[kennyliu]

Anyway, if I were to review the Playbook after OS 2 has been released along with most of the desired apps, I would say:

"The Playbook is a great tablet but we do not advise you to get one as it has a tiny power button and it's native calculator is so pathetic as it gives you 2+50%=2.5. What a deal breaker."

[pickles#WP]

For anyone who's upset at how the PB standard calculator handles percentages, simply use the "tip" calculator, instead. (While calculator app is open, swipes down and choose "tip calculator")

Input the number and the desired percentage. The PB will give you both the amount the percentage adds to the number and the sum of the number and the percentage.

[tharrison4815]

Just multiply the number by the resulting percentage. If you want 2+50% then you want 100% of 2 + 50% of 2. So 150%. So you enter 2x150%. This will give you the answer of 3 and technically this method makes more sense.

[kellands]

I started a thread recently about this very issue http://forums.crackberry.com/blackbe...k-what-691535/, whilst not knowing that it had already been discussed (and yes I did search before starting the thread, just not well enough apparently).

The issue is not if the answer is correct for the input in to the calculator but what our perception of the correct answer should be.

For me I wanted the ease of hitting the % to calculate the increase by adding tax, ie �27.50 + 20% = �33.00.

My BB 9360 does this as they know that when your out & about in the shops & you need to either work out Tax or Discount (hopefully ) that's what you would use your phone for.

The PB on the other hand does not see the request that way & does the calculation the correct mathematical way & not the perceived correct way.

I would prefer to have the PB same as my phone as its the simple way with less brain use & I need to conserve that as much as I can.

[urbanguy]

Many desk calculators are intended for business use and interpret the 50% to mean "calculate 50% of the number recently entered". While not necessarily mathematically correct, the result is as expected for business use. This is why a percentage key is included on these calculators ... to shortcut common business needs. Adding a percent key as a shortcut for "divide by 100" is silly. The PB shouldn't have a percent key if this is all it does.

I like how Google deals with this. If you enter "2+50%" in the search field, it provides the answer of 2.5 and helpfully shows that it has calculated "2 + (50%)" to make it clear that it's treating the 50% as a stand-alone.

[gsr2nv]

I understand both sides of the discussion, and agree that the answer to 2 + 50% is 2.5. My problem is the discrepancy RIM has created among their product offering.

It seems most (if not all) of the BB Phones gives 3 as the answer, instead of 2.5. The playbook gives the correct answer of 2.5

Why can't RIM be consistent?

[kennyliu]

I understand both sides of the discussion, and agree that the answer to 2 + 50% is 2.5. My problem is the discrepancy RIM has created among their product offering.

It seems most (if not all) of the BB Phones gives 3 as the answer, instead of 2.5. The playbook gives the correct answer of 2.5

Why can't RIM be consistent?

It looks like Texas Instruments is not consistent either. Somebody mentioned that TI-BA gives 2+50%=3 and my TI-30X gives 2+50%=2.5.

[mdarscott]

Wow! That's hilarious! Just tried it on Windows XP Calculator and, sure enough,
2 + 50% = 3
I consider that an error and will never trust XP calculator again.

If this really bothers you (it shouldn't because PB calculator is working correctly) maybe you could ask for a configuration option for how to handle the % key. Until then you could use the tip calculator which works the way you expect.

[cowpantswow]

The ONLY proper way the calculator should work is to calculate the % of the previous amount. Otherwise it is useless.
If I want to find out how what the value of x plus an additional 13% of it is then I would logically enter x+13%
If I wanted to know how much x+0.13 is then I would enter that!

Only in like 1998 would a calucator not work this way, except for scientific modes/types.
If x% is always x/100 what is the point of entering it that way. You can just enter 0.0X

But if you have to enter x + x/100*13 to get x+13%(of 'x') it seems like this is not fast or usefull in everyday lives.

Oh wait all those who seem to be hung up on this proper use of %
You would say, its easy just put in 5+5%*13 HOORAY!@@@@
BS; if I want to calculate how much somehting will cost with tax I add the xvalue of the tax% so in Ontario 10$ item is 10+13% tax is 10.13

Bottom line, make % to work as it expected for everyday use in normal calculator and leave the "correct" way for the scientific mode.
Btw having to use a tip calculator is not the answer and not even close to a real solution.

[Gazza12]

Quite frankly I don't give a damn as to what is mathematically correct. I only discovered this "fault" yesterday and the 6 people I showed it to couldn't believe it either.

I agree with others who say leave the mathematically correct to the scientific mode and let us use the calculator the way all 5 others in my house work ie 2 + 50% = 3.

Who has time to do the BS calculation shown by others?

Please let RIM fix this on the update.


It's a bit ironinc that on one of the most technically advanced pieces of equipment in memory we can't get a simple solution to 2 + 50%

[kennyliu]

The ONLY proper way the calculator should work is to calculate the % of the previous amount. Otherwise it is useless.
If I want to find out how what the value of x plus an additional 13% of it is then I would logically enter x+13%
If I wanted to know how much x+0.13 is then I would enter that!

Only in like 1998 would a calucator not work this way, except for scientific modes/types.
If x% is always x/100 what is the point of entering it that way. You can just enter 0.0X

But if you have to enter x + x/100*13 to get x+13%(of 'x') it seems like this is not fast or usefull in everyday lives.

Oh wait all those who seem to be hung up on this proper use of %
You would say, its easy just put in 5+5%*13 HOORAY!@@@@
BS; if I want to calculate how much somehting will cost with tax I add the xvalue of the tax% so in Ontario 10$ item is 10+13% tax is 10.13

Bottom line, make % to work as it expected for everyday use in normal calculator and leave the "correct" way for the scientific mode.
Btw having to use a tip calculator is not the answer and not even close to a real solution.

ok, you suggest that the percentage should apply to the last entered amount. now try calculating something like x*y+% or x^y+% or ....did you get what you wanted?

playbook's calculator does everything correctly. you have to specify the amount/number for which you want the %. otherwise it becomes an inaccurate shortcut of calculating things.

[rcm1301]

PB native calc: 100+10%=100.1
AIR calc: 100+10%=110

The intent for this statement is to get 110, not 100.1 (add 10% to 100) Also test if with 200 (200.1 vs 220).
Go check it on any handheld calculator, not just app.

Those Canadians are crazy and cannot do math. That is why the PB native calc lies in a folder called JUNK because it cannot be deleted.

[FF22]

PB native calc: 100+10%=100.1
AIR calc: 100+10%=110

The intent for this statement is to get 110, not 100.1 (add 10% to 100) Also test if with 200 (200.1 vs 220).
Go check it on any handheld calculator, not just app.

Those Canadians are crazy and cannot do math. That is why the PB native calc lies in a folder called JUNK because it cannot be deleted.

I will repeat a question I've asked before: add TEN PERCENT OF WHAT? I have ONE HUNDRED and now I'm to add 10% of what value?

But there is no way to settle this issue and every few months it crops up again. And then again.......

[Laridae]

I just went to try it on the calculator built-in to my cheap Android phone, but it doesn't have a % key!

I guess it may be mathematically correct to calculate the answer as 100.1 but it's statistically unlikely that's really what the person meant. That question is trivial and interpreting it that way is weird and unusual.

If you think about how people speak, it's far more likely they were asking about adding 10% of the first number, so I'd go with 110.

If our letter keyboards can guess which Word we meant then I guess it's only fair that our calculators try to guess what Calculations we really meant as well! Let's go with the Smarter calculator!

[drfleury]

I can't believe this silly discussion has gone on for three pages. If your doing a tax calculation it's a multiplication question first, then addition. If you use a little grade 4 common sense you would simply type 2 x 1.5 = to get your answer. In the lucky case of us in Ontario with 13% tax, 10 x 1.13 = 11.30. Or 10 x .13 = 1.13 for just the tax component. Your math teachers would be ashamed of you guys in here.
If you really want to use that little % symbol, type 2 x 50% then add that answer to you initial number.

[BlazorBoy]

Agree with the poster who observed that calculators ought not to have % keys. Also all ought to use RPN.

[jpash549]

My 25 year old RPN HP15c does: 2 enter, 50 ,%, plus to give 3. The visible ( x register) first shows the 2, then the 50 with the 2 going to the y register,then after the % key 1 and finally after the plus 3.
The point being ,besides how great RPN is, that you need to know how the register system operates and whether the % sign initiates multiplication.
The BBPB will give the right answer if you do: MC, 2,M+, *, 50%, MR, +. The sequence of operations is shown at the top of the screen.

[BlazorBoy]

Surely true, but what's wrong with 2*1.5? Easier on the fingers. Yet I guess it presumes a level of arithmetic familiarity inconsistent with today's high school grads.

[andyhlin]

Found a website that explains what the OP is expecting:
How does the calculator percent key work? - The Old New Thing - Site Home - MSDN Blogs

Basically, to an engineer or scientist, the Playbook calculator works perfectly fine.

By the way, regarding the Windows calculator, the mode can be switched to Scientific which disables the percent sign and follows the "order of operations".

[TheScionicMan]

I guess it may be mathematically correct to calculate the answer as 100.1 but it's statistically unlikely that's really what the person meant. That question is trivial and interpreting it that way is weird and unusual.

If you think about how people speak, it's far more likely they were asking about adding 10% of the first number, so I'd go with 110.

If our letter keyboards can guess which Word we meant then I guess it's only fair that our calculators try to guess what Calculations we really meant as well! Let's go with the Smarter calculator!

You assuming that a math program can discern what a person means or intended to say, but it needs to be more absolute than that.

100 + 50% leaves an open-ended question of "50% of what?. And as this thread has PROVEN, there's more than one way to interpret it... To finish that equation, it should read 100+50% of the original number = which is more easily and accurately expressed as 1.5

[hackerguy]

This whole thread is a perfect example of why math is the language of science. It is meant to be precise and give one an only one correct answer, not subject to interpretation. But, to use it properly you have to know and follow the rules. Too bad that students are allowed to advance without learning basic math skills.

[malanis5]

Ok, the fact that your calculator does it as some type of shortcut does not make it mathematically correct. The playbook is correct, and here is why:

Addition is commutitave, meaning that 2+3 yields the same answer as 3+2. This is the same for any values when added together.

Based on this fact, 2+50% should equal the same value as 50%+2. But if you do these two calculations on one of these calculators that you deem "correct," you will find that the former gives you a value of 3, while the latter gives you a value of 2.5. According to mathematical laws this is incorrect and impossible.

What a calculator should do, and what the playbook does, is read your input as 2+(50/100). Any calculator that does not yield 2.5 is providing you a shortcut, but is not correct mathematically. As an engineer it drives me crazy when I see this because it makes the calculator unpredictable. You expect the calculator to do math the way math is done and not provide unexpected "shortcuts".


Sent from my BlackBerry 9930 using Tapatalk

Thank you for this explanation. I have gone from hating my PlayBook calculator and thinking it was faulty, to loving it and realizing it is better than the average calculator for actually being more accurate mathematically!!!

[westronic]

I personally never use the % key because I never know how it will work.

If i want to add, say, 15% of a number to that same number, I would just multiply it by 1.15.