How Do Electronic Calculators Work

Tapping numbers into a calculator sure is easy, with your numerical query answered in seconds. However, with each sum a series of complex processes and components come into play.

Components first. A standard calculator includes a plastic casing, rubber button matrix, circuit board, single-chip CPU, battery array and liquid crystal display (LCD). More advanced models come equipped with a solar cell stack and/or integrated memory chips -the former used to charge the internal battery with the Sun’s energy, and the latter to store advanced calculations or equations.

Now let’s move on to the processes. Take a sum like ‘2 + 2’. When a user presses the 2 button on the rubber matrix, it deforms, forcing a bottom-mounted electrical contact onto the circuit board below and creating a connection. This causes electricity to flow to a pair of transistor switches on the board that convert the current into an on-off binary equivalent (a combination of is and os).

Next, when the V button is pressed, the inputted 2 is stored in its binary form by the calculator’s CPU, before resetting the input state to a receptive position. After the next 2 is inputted, the CPU sends both numbers to a logic gate as soon as the ‘=’ sign is hit.

Calculators – How do they work

Logic gates are electrical circuits with two inputs and only one output which execute logical operations that, in this context, are the adding, subtracting, multiplying and dividing processes. The inputs are sent in binary form to a logic gate, processed and then outputted as a single output – ie the number 4 in binary code. Finally, the answer is routed to the device’s LCD, where the digit 4’s binary is converted into segmented, illuminated lines that can be read off the display bar.