## Zero isn’t nothing

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When there are a lot of zeros after a number, it’s easy to add or drop some. Apparently.

Two examples: there’s an email that was going around in September about the proposed Federal Bailout Plan. The plan at the time was proposed to be around \$700 billion, and the author of the email pointed out that if this was divided by the 200 million or so adults in the United States, it amounted to around \$350,000 per person, and the author suggested that a better solution would be to mail a check for \$350,000 to each person instead. Now before you go looking for ways to spend the money, you need to double check the math. It turns out that \$700 billion divided by 200 million adults is only \$3500/person. No small amount, to be sure, but not quite enough to pay off the mortgage. [Note: Variations on this suggestion appeared on several websites with different numbers, but they were all off by a factor of 10 or 100.]

The web sites that posted this quickly caught the mistake and made a correction. And all was well. Except that this pesky problem of the wandering zero just appeared again. This article in The Guardian (and repeated elsewhere) begins:

Nuclear power plants smaller than a garden shed and able to power 20,000 homes will be on sale within five years, say scientists at Los Alamos, the US government laboratory which developed the first atomic bomb….’Our goal is to generate electricity for 10 cents a watt anywhere in the world,’ said John Deal, chief executive of Hyperion. ‘They will cost approximately \$25m [£13m] each. For a community with 10,000 households, that is a very affordable \$250 per home.’

Feelings about neighborhood nuclear reactors aside, there’s a little problem with the math. \$25 million divided by 10,000 households is \$2,500 per home, not \$250.* Perhaps still affordable compared to the cost of heating one’s home in the wintertime, but illustrative of the care that one needs to take when dealing with really large numbers. Especially when it comes to bailouts or nuclear reactors.

*an error originally caught by Classical Values