Fletcher's checksum
Have you ever played a game where you have to count the number of cars on the road or the number of birds in the sky? Sometimes we make mistakes and count it wrong. This can happen when computers communicate with each other too. If we send information from one computer to another, we need to make sure that it doesn't get messed up on the way.
Fletcher's checksum is a way of checking if the information we send has any mistakes in it. It works like this:
First, we take the data we want to send and split it into little pieces. We then group those pieces in pairs and add them up.
Next, we add up the results of those pairs.
Finally, we take that number and add it to the sum of the individual pieces.
This final number is called the checksum.
Now, when we send the information to the other computer, we also send the checksum. The other computer then does the same calculations with the information it received and compares the checksum it got with the one we sent. If they match, then that means the information was transmitted correctly.
Kind of like when we play the counting game, we have to double-check our count with a friend to make sure we counted everyone correctly. Fletcher's checksum is like double-checking to make sure our computer communication is correct too!
Fletcher's checksum is a way of checking if the information we send has any mistakes in it. It works like this:
First, we take the data we want to send and split it into little pieces. We then group those pieces in pairs and add them up.
Next, we add up the results of those pairs.
Finally, we take that number and add it to the sum of the individual pieces.
This final number is called the checksum.
Now, when we send the information to the other computer, we also send the checksum. The other computer then does the same calculations with the information it received and compares the checksum it got with the one we sent. If they match, then that means the information was transmitted correctly.
Kind of like when we play the counting game, we have to double-check our count with a friend to make sure we counted everyone correctly. Fletcher's checksum is like double-checking to make sure our computer communication is correct too!