Shout-out to the mathematicians in the house!
A "joke" (aka a teachable moment):
The renowned cosmogonist Professor Bignumska, lecturing on the future of the universe, had just stated that in about a billion years, according to her calculations, the earth would fall into the sun in a fiery death. In the back of the auditorium a tremulous voice piped up: "Excuse me, Professor, but h-h-how long did you say it would be?" Professor Bignumbska calmly replied, "About a billion years." A sigh of relief was heard. "Whew! For a minuted there, I thought you'd said a million years" (115).
The world is gigantic, no question about it. there are a lot of people, a lot of needs, and it all adds up to a certain degree of incomprehensibility. But that is no excuse for not being able to understand--or even relate to--numbers whose purpose is to summarize in a few symbols some salient aspects of those huge realities. Most likely the readers of this article [in Scientific American] are not the ones I am worried about. It is nonetheless certain that every reader of this article knows many people who are ill at ease with large numbers of the sort that appear in our government's budget, in the gross national product, corporation budgets, and so on. To people whose minds go blank when they hear something ending in "illion," all big numbers are the same, so that exponential explosions make no difference. Such an inability to relate to large numbers is clearly bad for society. It leads people to ignore big issues on the grounds that they are incomprehensible. The way I see it, therefore, anything that can be done to correct the rampant innumeracy of our society is well worth doing.
As Kent suggested on an Obsidian Wings thread about paying the cost of our current war in Iraq, these numbers can become much more real when split into cost-per-taxpayer or cost-per-household.