Q:  How many craters of size 0.1 km should form in 1 million years?
          About 10, based on the graph below (see uppermost circle)

  Q:  How many craters of size 1 km should form in 1 million years?
          About 0.001 (see middle circle) 

  Q:  How many craters of size 10 km should form in 1 million years?
          About 0.000 01 (see bottom circle)