There’s really not too much design thought going into calculators these days. Probably because their use is on the decline. But for those who still need one, this Draw it Yourself Calculator can be whatever you want. It starts off totally blank, you can fill in the numbers (stencil included) if you wish, or write them however you want. Draw, doodle, sticker, paint, whatever you can think of, you can make this calculator into. Solar powered too and you don’t even need to draw the sun on it (but you could).
Drawing: 48 Incredible Tips on Drawing for Beginners. Teach Yourself How to Draw Cartoons With This Drawing for Beginners Book (how to draw, drawing, things to draw)
Doodling with Jim Henson: More than 50 fun & fanciful artistic exercises to inspire the doodler in you!