Bi-quinary coded decimal

Bi-quinary coded decimal (also known as BCD) is a way to store numbers using only two digits: 0 and 1. It is similar to the way we write numbers with 0-9 on paper. Instead of writing 10 as a single digit, in BCD we write it as two digits, 01. This way it's easier for computers to understand and keep track of numbers. To remember how it works, it might help to think about the two digits like counters. When one counter reaches its maximum counting value, like when it reaches 9, the other counter starts counting from 0 again. This way, we can count to much larger numbers than with traditional counting.