Signed and Unsigned Numbers

"Signed and Unsigned Numbers"

• A binary number may be positive or negative. 
• Generally, we use the symbol “+” and “–” to represent positive and negative numbers, respectively. 
• The sign of a binary number has to be represented using 0 and 1, in the computer. 
• An n-bit signed binary number consists of two parts—sign bit and magnitude. 
• The left most bit, also called the Most Significant Bit (MSB) is the sign bit. The remaining n–1 bits denote the magnitude of the number.
• In signed binary numbers, the sign bit is 0 for a positive number and 1 for a negative number.
• For example, 01100011 is a positive number since its sign bit is 0, and, 11001011 is a negative number since its sign bit is 1. An 8-bit signed number can represent data in the range –128 to +127 (–2⁷ to +2⁷–1). 
• The left-most bit is the sign bit.