Sign Magnitude

The need to learn the conversion techniques between decimal and binary systems is mainly because humans usually give input to computers in decimal numbers, because that’s how the human world mainly operates, and while returning the computational result back to the human, computers need to make the output understandable for humans. But as far as computers are concerned, there is only a binary world. Hence the need for a system of conversion between decimal and binary. When it comes to numbers, there are two things computers need to do: represent them in binary, and then equally importantly, computers need to be able to perform arithmetic operations on those binary representations. Speaking of the representation of numbers, we often use negative numbers in our daily routines.

Negative numbers

Signed numbers are also really important in mathematical manipulations. The convention in the decimal system is to add a preceding “$-$” to the positive representation to denote that a number is negative. In a computer’s memory, there are only two symbols, 0 and 1, so there’s nothing to represent the minus sign with. So, some effort must be made to represent signed numbers. There are three different representations of signed numbers in binary. The simplest of them is the sign magnitude, which we’ll look at in this lesson.