Give each child a 2.5 cm (1") square construction paper template frame.
Ask everyone to place the square randomly on a well grassed area about 3m by 3m (10' x 10').

Each child counts the number of blades in his or her square.
The sum of the blades in all the samples is found and averaged.
This figure provides a base for calculating the size that an area would have to be to contain a million blades of grass. 

This is a great problem to donate to a willing eighth grade class to solve.

Encourage children to visualize a hot dog replacing each tiny blade of grass.
Then introduce the word "googol" and note that this term represents all the units that would be contained in a million staked-out plots.

Challenge them to express "googol" in numerals (a 1 followed by 100 zeros).