system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do one-digit numbers are up to 9 and not more? Why 10 is a 2-digit number and cannot be written as one-digit?

I know it might sound as a silly question but to explain better, why numbers are like 1,2,3...,8,9,10,11,12 and not 1,2,3,4,5,10,11,12 ... 15,20 when 10 would be equal as 6, 11 as 7, etc. With the same concept could we use 10 as one-digit with a new symbol? Would there be any problems in mathematics?
gpt
No problem in math. What you are talking about is the base. For example, in base-16, or hexadecimal, the numbers are 0123456789ABCDEF, where A is the decimal (base 10) value of 10.

It doesn't break math at all. Just how the numbers are represented.

As for the why, we use base 10 because we have ten fingers.