Greg Evenson, age 9, of Hopewell, Virginia, for his question:

Do the numbers ever end?

Our numbers have a beginning so we might expect them to have an end. The smallest number, of course, is one but the biggest number seems to be way out of sight. Actually, numbers really could go on and on and on forever, getting bigger one by one. We can add zeros to the bigger numbers so that they can jump ahead in tens. A million is one with six zeros and it would take you weeks to count it one by one. In a whole lifetime, you would not have time to count to a trillion, which has twelve zeros.

A septillion has 24 zeros. If you wish, you can invent even bigger numbers by adding more zeros. Somebody invented the googol, which is one with a hundred zeros. The biggest number invented so far is the googolplex which is many, many times bigger than a googol. But even the googolplex is not the end of all possible numbers.