when we normally count we go 0123456789 ...then we use them again 10-11-12...
binaries have only two numbers,,, 0 and 1... so 2 is the number to remember
2^0 is 1 (dont ask me why...)
2^1 is 2
2^3 is 8 (2*2*2)
so you start at the left side...
---^0
--^1-
-^2-
^3---