Quantity   Component name
1 × evive arduino powered embedded platform For more info - http://evive.cc/
1 × 4X4 keypad you can buy this on - http://www.ebay.in/itm/151964034460?aff_source=Sok-Goog
1 × breadboard a long breadboard for the
1 × Dupont jumper cables as many as yu want
1 × breadboard wires enough quantity to power the switches
9 × pushbuttons pushbuttons of different colors wil be nice
9 × resistors to pull down the switches
1 × write-able tape to make your calculator understandable and good looking