Code: The Hidden Language of Computer Hardware and Software

by Petzold Charles

You might recall that 10 binary digits are approximately the same as 3 decimal digits. By that I mean that 10 bits set to 1, which is 3FFh in hexadecimal and 1023 in decimal, is approximately equal to 3 decimal digits set to 9, or 999. Or 210 ≈ 103