July 11, 1987, was the Day of Five Billion, marking not only the extraordinary global headcount, but also the day the United Nations put forth programs and plans focusing on the important population issues affecting our planet.  Over 20 years later, there are one and a half billion more human inhabitants. 

Tip:  While teaching or showing your child what is a billion might be a stretch, you can certainly start to teach him or her about averages.  For your little ones, have them help you count how many people are in your neighborhood or the house/apartment on each side of your own.  Older children may be able to help you compute the average number of people by doing some division on their own.  For those that are not ready to try their hand at long division, show them what you are doing on a calculator to get to an average number of people per house or apartment.  And just as important as celebrating how high they can count or how well they can do long division, is to make sure they know that ONE person can make a difference in our big, big world and that the one person can be them!