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Good morning, Professor Reyna here. I get a lot of interesting questions in the mail these days, like this one from a little boy in rural Massachussetts:




Well, Mr. Peri, let's do a little experiment. Take a dollar bill out of your wallet. Hold it up to your computer screen over the green area below. Now, use the plus and minus buttons to size the area so that it's the same size as your bill. When you're finished, press the Continue button.