The best calculator is probably quickly-gotten and easily-dismissed:
hot key to pop up, type formula (input bar already has focus), hit Enter,
hit Copy key (result is pre-selected), Escape to dismiss calculator
entirely, hit paste key. No mouse, no looking at the screen, even.
That's a nice idea for power users, but no use for most, especially
Abby. It must be easily discoverable, and easily laid out.
Seth's idea of the napkin-back calculator is great, maybe if it could
hang off the panel and always be in front so that users could quickly
use it, then dismiss it. If after clicking the 'Calculate' button the
answer pane was highlighted and maybe copied, it would be fast to use..
is such behaviour inconsistent therefore bad for Abby's overall world?
I like the direction for the panel too.