Question

how do u represent negative numbers in binary?

Answer 1

it depends on how you want to do it... For example you can write -0000 0001 which is -1

Answer 2

or you can use two's complement

Answer 3

Two's complement or a sign flag.

Answer 4

normally the left most bit represents positive or negative, never have seen a -00001 before.

Answer 5

If you're asking about how computers represent negative numbers in binary, then it's, as @MaryMarvel stated, by using the two's complement notation.
Two's Complement Notation is used to represent signed binary numbers. The Two's Complement of a number is all its bits reversed, plus one. (i.e: The Two's Complement of A is NOT A + 1)

So -50 for example is represented as follows: 11001110
The Left-most bit is the sign bit, when it is 1 the number is negative.
So how to convert 11001110 to its decimal form?!
It's done as follows: 1st) Get the two's complement of it, that is:
00110001 + 1 = 00110010
2nd) if you convert 00110010 to its decimal form you'll get 50 and since the number is negative then the answer is -50
hope you got it

Answer 6

you said -50 is : 11001110, how do you know that that number in binary isnt realy 206? how do u know that its a negative number... @KimoKiko

Answer 7

http://en.wikipedia.org/wiki/Signed_number_representations

Answer 8

It all depends on if you are using signed or unsigned bits.

Answer 9

The -50 example is using twos complement: http://en.wikipedia.org/wiki/Two%27s_complement
You know the convention before you work it, signed bits or twos complement.

Answer 10

oh, u know if ur dealing with a neg or pos number... its not just like , u see 1's an 0's and u need to find the value... bec that could be hard., right?

Answer 11

You should be told if you're dealing with an unsigned or signed number. If signed then it will be half of an unsigned. I.E., a byte is 256 bits, so a signed byte would be -128 to 127. An unsigned would be 0-255.