In BASIC Calculator mode, how can you hide the *full equation*? Really annoying.

Sorry, there is no way to hide it.

You can submit feedback to Apple if you would like to see this option implemented.

click here ➜ Feedback - MacBook Pro - Apple

There are lots of other calculator apps available in the App Store. A popular one seems to be PCalc. It's not free but lots of people think it's great. I don't know if it does what you want but worth looking at.

You can't.

...but at least they don't make you pay for the "paper".