terminology - What is the proper term for the position of a digit within a number?

I am writing documentation for a code base, and I want my documentation to be as clear and unambiguous as possible. I am searching for the proper term to refer to the position of digit within a number.

Take the number, 00100000, and I want to refer to the position of the 1. So far I have come up with bit "placement"; however, this is unclear as to which direction the bit placement increases, without further explanation. I know that the leading bit is referred to as the "most significant bit", and the rightmost is referred to as the "least significant bit"; therefore, would it make sense to use the term bit "significance", or is there a mathematical term to describe this?

Example of how I plan to use the term: The placement of the 1 is 5, or the significance of the 1 is 5.

Answer

In a positional numeral system, each digit's weight is determined by its position in the numeral.