Using this method (and other related "test" functions) I discovered that the default iOS calculator operates with significantly greater precision that the popular third party "PCalc", which was a little disappointing.
It implements the HP42, but with a math library w/ 34 decimal digits of precision. You can also buy a calculator, the DM-42 that runs on it and itd be the best calculator in the world if the key board weren't so… bleh
Also heads up: the automod seems to have banned you. I had to vouch this comment. You might be commenting too fast for a new user or be commenting from an IP it doesn't like.