maths question

[hollyuk]

Does anyone know why you can't divide by zero?

Thanks!

[DaisyMae]

I have no doubt that there is a perfectly good mathematical answer to this question, but I shall try and use simple logic to explain what to most people would appear quite obvious.

Zero represents nothing, therefore if you divide anything by nothing you have not divided at all.

I hope this is clear.

[BigDave44]

If you think of division, as computers do, as repeated subtraction, then to divide by a number you count the number of times that you can take it away until you are left with zero or a number less than the divisor.

e.g. 7 / 2 = 7 - 2 - 2 - 2 gives 3, remainder 1

Try the same thing with zero and the answer is always infinity, except for the special case of 0 / 0 which is indeterminate

[mohill]

another way of thinking of it is as follows:
the fraction a/b means... what can you multiply b by so as to get a?
eg 12/3 means what can you multiply 3 by so as to get 12?
3x4=12 so the answer is 4
When you have a number over zero then there is no possible solution.
eg 23/0 means what can you multiply 0 by to get 23?
0 times any number is still 0
So mathematically, any number over zero is DEFINED to have no meaning.
any number over 0 TENDS towards infinity and it is both convenient and satisfactory to accept and use this idea.
cheers

[flobadob]

Why can't you just say anything divided by zero equals zero? For example if I had 4 pies and gave one to each of four people and no pie to a fifth person, could I not then say, to each person with a pie, you have got 1 of 4 pies or 4/1 and to the fifth person you have no pie or 4/0. Perhaps not, but why not, it would work mathematically. I remember one time in school the teacher was saying 0/0=1 but I was arguing that 0/0 should be 0. He didn't take me on and we moved on.