What is the smallest number in number system?

Answer 1

Numbers never end, therefore there is no smallest number only smaller than the last.

But it depends on the number system that you are defining, and what you mean by smallest - is is smallest magnitude, or a number which everything else is greater than it. For example, if you are dealing with natural numbers [counting numbers: 1,2,3...], then there is a smallest number, which is 1. If you're dealing with integers, and you mean smallest magnitude, then zero would be your number, but all of the negative integers are less than zero. What if your system is 8-bit signed binary numbers (so the range is -128 to +127). So you need to be specific about what you are looking for.