Calculator Wrong Answer

[hitec]

Today I was double checking some numbers and according to the Droid Calculator 3279.18 - 3278.78 = .3999999
Can anyone confirm this happens with theirs?

Further testing gives the correct answers
9.18 - 8.78 = .4
79.18 - 78.78 = .4
279.18 - 278.78 = .4

I am running Chevy 1.25GHz ULV on Simply Stunning 4.4. Slowing down the CPU does not affect the calculator results at all.

 

[BobthePhotoGuy]

interesting

same answer here

 

[BigMcGuire]

Mine does the same. BB .4 (Froyo) with Chevy's ULV 1.0Ghz.

 

[dolpns13]

same here. For some reason it isnt rounding up

 

[JCo352]

I get .3999999999 but I have a calculator from some other phone I cant remember what it is though.

Edit: It's from the Desire.

 

[dolpns13]

excel give me .4

 

[jacobrv]

It is not a rounding problem, it is a problem with how floating point numbers are stored in computers. My suggestion, download RealCalc Scientific Calculator from Brain Overspill. That's the one I use, and when I tried your problem it worked fine.

For more info on floating point numbers see here: https://secure.wikimedia.org/wikipedia/en/wiki/Floating_point

EDIT: In the built in calculator I did get .3999999.

 

[Joker]

That's interesting. I get the same answer as well. I guess I will have to get that RealCalc app mentioned above. Thanks for the heads up.

 

[hitec]

Thanks everyone for confirming that is was not just my droid. I thought it was interesting that the floating point error shows up in a simple subtraction.

jacobrv. Thanks for the heads up on RealCalc. It is overkill for most of my needs, but the main thing I want in a calculator is a correct answer.