I was studying the conversion technique between Hexadecimal and Binary where
For example
$4C2_{16} = 010011000010_{2}$
Can be done by substituting 4 bits for each Hexadecimal digit.
Why is it so easy to achieve this conversion to binary by combining a series of 4 bits to represent each Hexadecimal digit?
This obviously does not work for decimal to binary conversions, but I am not too sure why either.
For example
$15_{10} ≠00010101_{2}$