Number layout phone vs calculator

[Elckerlyc]

That is interesting. But I think, if the RPN was to be used, the sum would have been written down differently. Something like: 130 100 + 5 x
But I am not really familiar with RPN. It is I think only used in financial circles, not in administration.
In everyday's use the common rules apply.

PS
And I think you should get a better calculator (one that stacks your input before doing the calculating.)

 

[Swank]

The calculator does not have rules built into it - it is just doing the sums in the order they are typed in.

The phone is a computer. It can look at the compete sequence and apply order of operation rules that a calculator has neither the capacity nor programming to accomplish.

The 1150 result is painful because it means that the calculator app on the phone isn't working like a calculator. And if you don't know how it works, that could be an issue.