Developmentally inappropriate for 7 year olds?
 less than 100: 99 [2 nines, 2 zeros]
One less than a trillion? How many nines?
One less than a googol?
One less than 10^n?
One MORE than 10^10? What is the SUM OF THE DIGITS?
YOUR STUDENTS' IDEAS?
***STATE A RULE - YES!***
***MEMORIZE? NO! NO! NO!***
OR ignore all of this!