Mathematics is such a good science! Everything is so logical... The whole universe can be described with ten digits only. But, does it really have to be like that? Do we need exactly ten digits? Of course not, it is only a matter of habit. Remember the lessons from the school. For example, what does the number 764 mean: four units, six tens and seven hundreds. It’s as simple as that! Could it be described in a more complicated way? Of course it could: 4 + 60 + 700. Even more complicated? Yes: 4*1 + 6*10 + 7*100. Could this number look more scientific? The answer is yes again: 4*100 + 6*101 + 7*102. What does it actually mean? Why do we use exactly these numbers: 100, 101 and 102 ? Why is it always about the number 10? Because we use ten different digits (0, 1, 2, ... 8, 9). In other words, we use base-10 number system, i.e. decimal number system.