My Garden, Insects ... and Math

"There are about as many insects in one square mile as there are people in the entire planet."
I found this quote in the National Geographic Kids magazine, February 2009 issue.

So, mom came up with the question of how many insects are in my garden.

My garden is 150 square feet.
1 square mile = 27,878,400 square feet
There are approximately 6.77 billion people in the world.

6,770,000,000/27,878,400 = x/150
242.84 = x/150
(150)(242.84) = (x/150)(150)
36,426 = x

There are approximately 36,426 insects in my garden!
WOW! That's a lot of bugs!