Using the system without zero that you mentioned earlier, there is no natural number that represents the approximation of zero. However, we can use a sequence of natural numbers that approaches the symbol * to simulate a division by an approximation of zero.

For example, we can consider the sequence (an) defined as an = 1/n, which approaches the symbol * as n approaches infinity, but never actually reaches it since * is not a natural number.

Therefore, we can write the expression 5/(aprox) as 5/an, which simplifies to 5n. As n grows larger, the value of 5n approaches the symbol *, which can be interpreted as an "approximation" of 5/[0) in this sense.

However, I must emphasize that this is not a well-defined mathematical operation, and such manipulations should be used with caution, if at all, as they do not align with standard mathematical practices.