Binary for Decimal Numbers

[emerger]

Hello. Am taking a class and we had to convert decimal numbers to binary. While trying to understand the code to do this, I found out that all numbers less than .5, in binary, begin with a 0. While all numbers after .5, including .5, up to .99999 begin with a 1 in binary. Can anyone explain why this is?

[Larz60+]

It's called two's compliment arithmetic.
see: https://www.cs.cornell.edu/~tomf/notes/c...scomp.html