Those who understand binary...can...

[suprasteve]

you mean with the exponent and mantissa and all that? yeah that's a little harder to explain

 

[Dngrsone]

you mean with the exponent and mantissa and all that? yeah that's a little harder to explain

Still powers of two, just on teh negative side.

For example, 00.10 would be .5 decimal, 00.01 would be .25 decimal, then .125, and so on.

The US Navy, realizing that all their technical types used calculators with built-in bin-dec-oct-hex functions went to using the above on their tests to make sure the techs actually had a clue about the binary numbering system.

 

[ceewi1]

And if we want to go even further into binary we can look at the representation of negative numbers (twos complement). Seems we're starting to drift though

 

[suprasteve]

for singles and doubles, don't you just make the first bit a 1 and that make it negative?

 

[ceewi1]

You're thinking of sign bit notation. Twos complement is used so that mathematical operations (binary arithmetic) still works with positive and negative numbers. It also elimenates the two possible representations of zero.

Basically, you invert the bits (take the ones complement) and add 1.

For example the number 5:

0000 0101 (5)
invert: 1111 1010
add 1: 1111 1011 (-5)

 

[Hellbreather]

ceewi you add 1 at the end -5 in twos complement is

(1)1111 1010