# Why we can’t divide by 0

Quite rarely do I ever do anything about mathematics on Tweaked for your Pleasure but today I got e-mailed a question and although I rarely do requests, I figured I might as well ask this.

Basically, the e-mail was as follows:

Hi Matt

just wondered as you are good at maths why i am told 0 divided by anything is not possible. Mind explaing ?

Thanks

Bad English aside, the answer is below.

The simple answer is because we simply can not define the outcome as we can not decide on any rules that will stick for all inputs. So for example we could have;

• $\frac 1 0 =5$

There is a rule within arithmetic that means $(\frac b a) = b$ and following this rule and what we defined a minute ago that if we do;