What happens when you press a button on your calculator ? [Calculator Tricks Series]

Welcome to our new episode of the “Calculators Tricks ” Series .

Today , we will discover what happens when we press a button on your calculator .

Press down on one of the number keys on your calculator and a series of things will happen in quick succession:

As you press on the hard plastic, you compress the rubber membrane underneath it. This is a kind of a miniature trampoline that has a small rubber button positioned directly underneath each key and a hollow space underneath that. When you press a key, you squash flat the rubber button on the membrane directly underneath it.



  1. The rubber button pushes down making an electrical contact between two layers in the keyboard sensor underneath and the keyboard circuit detects this.
  2. The processor chip figures out which key you have pressed.
  3. A circuit in the processor chip activates the appropriate segments on the display corresponding to the number you’ve pressed.
  4. If you press more numbers, the processor chip will show them up on the display as well—and it will keep doing this until you press one of the operations keys (such as +, −, ×, ÷) to make it do something different. Suppose you press the + key. The calculator will store the number you just entered in a small memory called a register. Then it will wipe the display and wait for you to enter another number. As you enter this second number, the processor chip will display it digit-by-digit as before and store it in another register. Finally, when you hit the = key, the calculator will add the contents of the two registers together and display the result. There’s a little more to it than that—and I’ll go into a few more details down below.

Find the Full Article HERE