How many real numbers are there? One answer is, "Infinitely many." A more sophisticated answer is "Uncountably many," since
Do numbers ever end?
The sequence of natural numbers never ends, and is infinite. ... So, when we see a number like "0.999..." (i.e. a decimal number with an infinite series of 9s), there is no end to the number of 9s. You cannot say "but what happens if it ends in an 8?", because it simply does not end.
What is the largest number?
The biggest number referred to regularly is a googolplex (10googol), which works out as 1010^100. To show how ridiculous that number is, mathematician Wolfgang H Nitsche started releasing editions of a book trying to write it down.