00:01
So here we've got this exercise where we're looking at a bunch of binary patterns that are using two two's complement.
00:09
And we want to add them all together.
00:11
So remember two's complement says that if you have a leading one, then that value is negative.
00:17
And let's just do addition in normal ways.
00:20
So look at the rightmost column and see one plus zero makes one.
00:25
Zero plus zero makes zero.
00:27
And so on just like that.
00:29
So now we've got part b.
00:32
One plus one in binary, that's going to be zero with a one being carried over.
00:39
That's what i've got right here.
00:41
One plus one plus zero is zero with a one carried over.
00:46
And you can see how it just sort of cascades from here.
00:51
This is exactly what we've got.
00:53
Now there's two interesting things about part b.
00:56
The first is that we can stop right here.
01:00
We're only using five digits.
01:03
The sixth digit, normally you would want to carry it over, but in two's complement, we are just truncating it to only five digits.
01:11
So our answer is going to be zeros.
01:13
Is this correct? well, in two's complement, a string full of ones means negative one.
01:20
This is essentially negative one plus positive one...