5 cannot be divided with 0.

but 0 can be divided with 5. 

Examples:  

0/5 = 0 correct

5/0 - is incorrect 

numbers cant be divided at 0 like 4/0 or 3/0 this is a big mistake...

but 0 can be divided at numbers like 0/4=0 0/20=0 0/15=0.

One of the main reasons it's undefined is because of the dilemma it presents. It seems to make sense that 0/0=0, right? Since 0 * 0 = 0. 

However, let's think about another case. When you divide anything by itself, the result is always one. For example, 5/5 = 1, 2/2 = 1, and so on. 

So, by that logic, we seem to have two different answers. 0/0 could be 0, by your line of reasoning, or it could be 1, by another line of reasoning. That is another intuitive justification as to why it is undefined; the answer seems to be either 0 and 1. 

Let us assume, you would not divide by zero but by a very small number like 0,00000000001.

The number you would get will get pretty large. The closer you get to the real Zero the larger the result will be.

Practically you are each Time multiplying the number with the reciproc number of that smaller getting number.

10^(-15) becomes 10^15 resulting in getting a number that gets closer and closer to „infinity“.

Since there is no real number called infinity or it is hard to handle „infinity“, dividing something by zero is not „defined“ (and causing an overflow)