Whenever we are dealing with numbers in our daily lives, we use the so called decimal system. This means that our entire counting system is based on the number 10. A given number, for example 17, actually means „1 time the number 10, plus 7 times the number 1“. It’s the same as counting with your fingers. Once you reached 10, you remember the result and start over again with one finger.

Now what if we had 8 fingers instead? Our counting system might be based on the number 8. This would be called octal system. Our decimal number 17, also called 17_dec to prevent confusion, would instead be written as 21_oct, which actually stands for „2 times the number 8, plus 1 time the number 1“.