[aaronz8]

Wow! I remember doing this to my and my friends' 4-function calculators in 5th grade! This was actually how I learned how LCDs worked.

You can also remove the reflective sticker on the back of the black and white LCD, to make it transparent where it was previously reflective. That's how I made my calculator work with our classroom's overhead projector. (and some really interesting pranks)

[Cthulhu_]

That's a pretty neat hack. Reminds me of a DIY projector where an LCD screen was stripped down and placed on top of an overhead sheet projector.