Here's a protective case designed for the CASIO FX-702P pocket computer. It fits slots on the body, allowing the case to be secured to either the front or the back through the slot.

You can print 3 parts separately and secure them with 4 M2x3.5 screws and 4 M2 nuts (I highly recommend this method for better strength), or you can print 720p_cover_whole.stl as a single piece.