Click stuff, use space switch between eraser and writing. Use the green flag to erase all.
The root thing systematically brute forces the answer by changing the precision and guess accordingly, inputting you guess can be very helpful to the speed. There are still some errors with it. if you find something incorrect put in zero for the guess. AAAAAAAAAAAAANNNNNNNNNNDDDDDDDDD you can't really cheat, because it's just something that's tedious to do irl so you usually get a calculator anyway.