Question

Binary subtraction
111 - 11001

Answer 1

I've used r's complement method but I get the wrong answer:
Two's complement: 00111
Adding them: 111+111=1110
Omitting carry: 110
And that should be my answer, except it's incorrect.

Answer 2

I have no idea how to do this stuff, so I just looked at an online binary calculator for you, and the result was this -10010 I've done binary addition before, but never this

Answer 3

That's the answer I'm trying to get to, the method above worked on every problem so far. But got stuck on this one.

Answer 4

Well, I have absolutely NO idea how to give an explanation for that, sorry :/

Answer 5

add backwards :)

11001
- 00111
-------
0 0+1=1, carry a 0
0



11001
- 00111
-------
10 1+1=0, carry a 1
10



11001
- 00111
-------
010 etc ...
110



11001
- 00111
-------
0010
0110


11001
- 00111
-------
10010
0110

Answer 6

111 - 11001

can be written in addition by 2comping the negative, swap out and add 1

111 + 00110 + 1

now add

00111
00111
------
01110

convert it back, swap and add 1

10001 + 1 = 10010

Answer 7

That's brilliant
Thanks for the alternative way, my brain was frying over the first one.