Sony Xperia ZR's Calculator is wrong

[Raze]

Hi,

First off, I tried to use my phone's calculator this morning, and found out that it doesn't work very well. For example,

45 + 45 - 45 x 45 = should be 2025

But it shows -1935 instead. I don't know why, and I don't know how to setting the calculator at all ( even if it was possible ).

Second, I checked that Xperia ZR should have Android 4.2 update, but it doesn't show on my Phone update or even on computer. How do I upgrade it then?

Thanks.

[Uliwooly]

Just noticed that issue, here are some alternatives

Algeo graphing calculator
https://market.android.com/details?id=com.algeo.algeo#?t=W251bGwsMSwxLDUwMSwiY29tLmFsZ2VvLmFsZ2VvIl0...

Function Inspector Lite
https://market.android.com/details?id=de.georgwiese.functionInspectorLite&feature=also_installed#?t=...

Mathmatiz
https://market.android.com/details?id=gcmath.ui#?t=W251bGwsMSwxLDUwMSwiZ2NtYXRoLnVpIl0.

Math Keyboard
https://market.android.com/details?id=will.droid.mathkeyboard#?t=W251bGwsMSwxLDUwMSwid2lsbC5kcm9pZC5...

MathScript Calculator
https://market.android.com/details?id=com.funmath.mathscriptlite#?t=W251bGwsMSwxLDUwMSwiY29tLmZ1bm1h...

[Uliwooly]

As for android 4.2 you have to wait for the update to be approved and released in your country. 

You have 2 options

1) wait 

or 

2) manually update your phone

keep in mind that if your phone is or was locked to a carrier/network branded, you have to wait for them to approved and release the update

Update Service (SUS)

http://www.sonymobile.com/gb/tools/update-service/

http://www-support-downloads.sonymobile.com/Software%20Downloads/Update_Service_Setup-2.11.12.5.exe

PC Companion (PCC)

Bridge (for Mac)

Alternatives on How to backup Xperias

http://talk.sonymobile.com/thread/36355

Don't forget to give Kudos (Click on the half star + )

[Raze]

So you're saying there's no way to fix that calculator?

Instead, you have to download an app to fix it?

Plus, how do I manually update it? By Rooting? no other way?

[Uliwooly]

as far as flashing 

How to manually update, downgrade, root 2013 Xperias

http://talk.sonymobile.com/thread/124152

Don't forget to give Kudos (Click on the half star + )

[Rickard · Accepted solution]

The calculator is not wrong. 45+45-45x45=45+45-(45x45)=45+45-2025=-1935

x and / is always calculated before + and -.

[coolhz]

Hello Rikard I use a Sony Xperia L and its wrong I noticed it while using normal trigonometric functions such as sin30 gives me −0.988031624 which actually come to 0.5 . I haven't used any other functions or numbers. Its wrong with tan and sin.

[JakeSully]

just did what you said it went even futher down to -5850 lol either i miss understood your message or so xD but i agree with guy doing 45+45-45x45 does make it -1985 for odd reason.

xperia z is phone i use and got same as guy who gets it on his ZR

[Rickard]

Unfortunately there's no setting to switch the calculator between radians and degrees. The calculator uses radians so the answer you're getting is correct but to calculate in degrees you need to download another calculator.

sin(30) in radians=-0.988031624 while sin(30) in degrees=0.5

[Rickard]

When mixing + and - with * and / in one (single) equation you need to consider something called order of operations. According to mathematical rules * and / should be calculated before + and - (unless you add () to the equation). Some simple calculators doesn't support this and gives wrong result.

So when you enter 45+45-45x45 that means that 45x45 will (and should) be calculated first.

To get the result you're looking for you would need to add () to the equation: (45+45-45)x45=2025 or don't type it as one equation (tap = for every step): 45+45=90, 90-45=45, 45x45=2025.

Wikipedia has some more information on order of operations: http://en.wikipedia.org/wiki/Order_of_operations