After all of the Citizen watches of the last few days, I'm using another C watch today - a Casio!
This watch allows you to be geeky and wear a calculator watch, without anyone seeing. I have fact, the colourful nature of this watch looks like a forerunner to the later Poptone watches.
The watch is the Casio Flip Top Calculator which was released around 1992. From afar, it just looks like a standard 3-hand dial watch, with the name on the face and the "pull-open" note on the bottom being the only hint to the other main feature. When you flip open the top, the calculator is revealed. It has a membrane type pad for the buttons which are arranged in a 60 degree offset arrangement. The calculator has the standard functions, but none of the extras you find on some calculators. The display is an LCD panel with up to 8 digits.
This model is the FTP-11, which is a colourful (and apparently purely cosmetic) update of the FTP-10. It has a 760 module which controls the dial (and has been used in other non-calculator watches).