How to add two 4-bit numbers
 

How do i add two four bit numbers, what are the steps required to do so?

What kind of equipment is available? Are you looking for a chart of NAND gates or a line of a C program or what?

No ,nothing like that, just how do i add two four bit numbers manually on paper. Like 0000 + 0001.

0000
0001
----
0001

It's the same like adding decimal numbers. The same rules apply.

I don't think so i'm talking about binary addition(base 2). I don't know how to do it. But i could use an example showing me what to do.

In decimal when you get to 10 you write a single digit in the current column and carry 1 to the next column (left, more significant). Binary is just the same except it's 2 that brings you to the carry - there are only two single digits 0 and 1.

There are on-line tutorials. This is a good one:
http://www.math.grin.edu/~rebelsky/C...student-binary

Daniel B. Martin

An example was already given.

Here's a few other examples:

It's exactly like base 10: 0 + 1 = 1 ... etc[/b] ... 1 + 1 = 1 carry 1.

It does take a bit of getting used two ... ;)

It's the same as adding in any other base. Base 2, base 8, base 10, base 16, it all works the same.

Start at the LSB, add the numbers together. If you overflow that digit (2 in base 2, 8 in base 8, 10 in base 10, etc), then carry the 1 into the next most significant column and repeat.

lol, clever

Like the much repeated phrase "There are 10 types of people in the world: those that understand binary and those that don't.".

Thank you, i've understood what to do :) Sorry laho guess i thought binary addition would be 'harder' than that.

Try subtraction :)
jlinkels

No prob. That's why computers use it because it's easy to do.

Good idea will check it out.

Start from here: https://en.wikipedia.org/wiki/Positional_notation .


Modern world appears to be completely dumbed down - we were taught the above at school, before age of 17.

No.

Computers don't care - they are not humans.

This is severely OT, but the description of number systems reminded me of former employer I worked for. The owner of that company was a genius, but also of a bit a nerd as happens so often with smart people. Our workstations were W 3.11, but for the servers etc he insisted on Solaris. This was 1992, so Linux was not really widespread.

He insisted on a standard file name convention, wich was FILENAME.YMD. 8.3 filenames only, remember? So to write YMD, we used that last digit of the year, the month in base-12, and the day in base-31. Base-31 is not difficult, just continue to use alphanumerics after F... After some practicing most of us could remember the ordinals of the characters by heart. I have been using this base-31 file extensions for many years after that, until the 8.3 filenames completely disappeared.

jlinkels

It is amazing how many programmers still use this incredibly short-sighted practice. Not just single digit years, 2 digit years are nearly as bad. In the next 40 years we are going to be facing a shitstorm of "if (2digityear < 50) then 4digityear=2digityear+2000 else 4digityear=2digityear+1900" breakdowns across the board. Even now, when file name and memory space restrictions are almost non-existent, I still see programmers using this practice all over the place.

It gets me all worked up...sorry about the tangent.

I think you are right about the laziness/shortsightedness of certain programmers, but with 8.3 filenames there was little other choice. Maybe 8.3 was not such a good idea.

jlinkels

I think that should be 1 + 1 = 0 carry 1.

My inner pedant emerges again. Someone should have noticed that after the old "10 people...." thing came up.

While tempting to bash Microsoft for the whole 8.3 filename thing, I'm fairly sure it was a deliberate choice to be compatible with CP/M.

--- rod.