A large 10" screen dedicated to a simple application like Calculator is just a waste of precious screen-estate, especially if you have to continually do some figures from one source and keep switching.

Android/Honeycomb doesn't address this issue and any fixes are usually via shortcuts which dont really solve the problem.
iPad has the same problem and similar solution, bummer.
Only WebOS and QNX seems to have this done right.

Until Cornerstone:
http://www.youtube.com/watch?v=QCpEKnUuGXY