Somebody pointed me at "Towards an API for the Real Numbers" which explains why these calculations work how you expect in the Android default Calculator.
It's really nice, as they explain you can't drop this in instead of the floating point arithmetic in a serious language because the performance isn't what you want. However in human terms, for a product like the calculator - it's easily fine.
It's really nice, as they explain you can't drop this in instead of the floating point arithmetic in a serious language because the performance isn't what you want. However in human terms, for a product like the calculator - it's easily fine.