Two's Complement Binary Addition

[shamieh]

I understand


1 0 1 0
+1 1 0 1
_________

=0 0 0

1 0 1 0
1 1 0 1
________
0 1 1 1

which becomes 1000

BUT, how does

1 0 1 0
+0 0 1 0
_________

not become
1 0 1 0

1 0 1 0
+ 0 0 1 0
___________
?

 

[HallsofIvy]

Re: Addition

We need more information. My first guess was that this was binary addition, but then (1010)+ (1101)= 10111 and (1010)+ (0010)= 1100. Is this a "twos complement" notation?

 

[shamieh]

Re: Addition

Solved

 

[MarkFL]

Re: Addition

Solved

Please DO NOT remove content from a post after help has been given. This devalues a topic, and voids the time given by the people trying to help.

This is prohibited by MHB rule #7:

Do not edit or delete questions after getting help. When a user edits or deletes a question after getting help, the context of the help is subverted and the thread becomes difficult for other members to follow. Moderators will close threads vandalised in this way, restore the deleted question, and the infract the offending member. The material posted on MHB is a body of knowledge that is a valuable resource for everyone. It is unacceptable to vandalize this resource. Note that a member who deletes a question after getting help casts suspicion of cheating upon themselves. Be careful what you post. Once you post a question or information, it will remain viewable to all members of the public - this includes all staff and students of the institute at which you may study - and may show up on search engines such as Google. It is good etiquette, if you mark your thread as [SOLVED], to post your solution so that others searching MHB will be able to see the solution, and not waste their search time.

I am using discretion here to not lock the topic nor issue an infraction, as I feel you were simply not aware of this policy, nor are you trying to cheat.

 

[shamieh]

Re: Addition

Lol HallsofIvy provided no help whatsoever. He was just asking me what I was actually asking. That's why i put solved. I figured out the problem by myself. But I will take note of this rule and adhere to it for the future.

-Sham

 

[MarkFL]

Re: Addition

...HallsofIvy provided no help whatsoever. He was just asking me what I was actually asking. That's why i put solved. I figured out the problem by myself. But I will take note of this rule and adhere to it for the future.

-Sham

When a question is unclear, then a good helper will ask for clarification...and this is actually an attempt or effort made to help, because before someone can offer good help, they must understand exactly what is being asked. HallsofIvy has a lot of experience giving help on math forums and so he knows it is better to get clarification than to try to give help based on assumption and interpretation. This can lead to wasted time and effort...something I learned the hard way.

It also help make MHB a more informative place, since future readers of the topic will also have no doubt about what is being discussed.