At a White House press briefing last week, OMB Director Peter Orzag repeatedly cited estimates that the budget deficit would run $9 trillion over the next decade--that's almost a trillion dollars a year.
The 21% correct response figure cited at the end of the video comes from a multiple choice survey given to a thousand American adults. A monkey throwing darts at the five answer choices they provided in the multiple choice version of their poll would hit the correct answer 20% of the time, so a 21% correct response rate is discouraging.
Search for Intelligent Life points out another video describing the public's bewilderment in the face of large numbers:
Edith Stokey and Richard Zeckhauser have a simple and sensible suggestion for getting a handle on large numbers: long division.
A useful number to keep in mind for back-of-the-envelope calculations is that the US population is roughly 300 million.
So the next time you read that the federal government is considering spending a billion dollars on something, you can think that's over $3 per American. And when the federal government considers spending a trillion dollars on something, that's over $3K per person.