Although you can buy your own calculator very cheaply you can learn a lot by building your own. Kale_3d has developed an Arduino based calculator that uses a keypad and an LCD display to your calculations.
The project is very well documented, including instructions on how to build the case, full code examples and a wiring diagram. This is a great project to learn about electronics assembly and coding and learn how to develop something more than a blinking LED! If you are keen to get started building your own calculator checkout the following link.
If you are looking for a rapid-use LCD for your Arduino or compatible projects why not check out the Freetronics LCD & Keypad shield. The shield contains a bright 16x2 character LCD and five buttons that can be read from only one analog input pin:
Did I mention that you can play games on your LCD Shield? Check it out!Inspired to create your own interactive coffee table? Working on a project you would like us to feature in this blog? Let us know in the comments section below or on Facebook and Twitter.