Judy Dallinger, age 11, of Yale, Ia., for her question:

Is there a number higher than the googol?

The numbers begin with one and go as high as we need them to go. Scientists often deal in staggering numbers, and the figures they use go far higher than anyone can count. No one could count even as high as a trillion, but much larger numbers than trillions are needed. The googol is an immense number that can be written as 10 followed by 100 zeros.

This staggering figure, you might think, is the number to end all numbers. But an even bigger figure has been invented. It is the googolplex. It is 10 multiplied by a googol number of times. If you feel impelled to write it out in ordinary figures, you would put down 10 and follow it with 1000 zeros.