eli5: How does an electronic calculator work?

Question

Does it “use” the most efficient approach when solving equations? For example I know a technique for solving larger multiplication or addition problems is to break the numbers up so you’re working with smaller sums. Ex: 60 X 4

60 X 2 = 120

120 X 2 = 240

Not to say that’s the most efficient. But what I’m wondering is if the calculator goes through some process (that’s the best process) of its own.

In: 4

Answer 1

A calculator first translates your numbers to binary. Instead of 7, it will be 0111.

It then does math more or less like you were taught to in elementary school. For basic operations like addition, it just starts with the one’s digit and adds then carries over to the two’s digit and so on.

This is all done in nanoseconds, comparing individual 1’s and 0’s as electronic signals in transistors.

Answer 2

A calculator first translates your numbers to binary. Instead of 7, it will be 0111.

It then does math more or less like you were taught to in elementary school. For basic operations like addition, it just starts with the one’s digit and adds then carries over to the two’s digit and so on.

This is all done in nanoseconds, comparing individual 1’s and 0’s as electronic signals in transistors.