[thejteam]

I went to a very good public school system in Maryland. More than one math teacher taught me that while we suspect that there are an infinite number of prime numbers, we can't prove it. I found out later that there exists a relatively simple proof known to Euclid. Lots of college students honestly believe that 0.999… (repeating 9's) is NOT exactly equal to 1. My upper level analysis teacher spent an entire class period dispelling this myth. We were all taught the wrong answer by multiple public school teachers in many different districts. Now, is the teaching of creationism any worse than teaching wrong math? If public school teachers can't get cut and dried math facts right, how many are going to be able to understand the nuances between "hypothesis", "theory", "law", etc?

[tmzt]

Do you have any reference/proof/etc. for 0.999... === 1? As one of those taught to believe it is not, I would like to see it.

Unfortunately, text books conserve non facts for very interesting reasons. Some good examples are at http://www.textbookleague.org/

[thejteam]

A very informal proof:

Let X = 0.999… Then 10X = 9.999…

10X - X = 9.999… - 0.999… = 9 = 9X Therefore X = 1.

Being able to do the subtraction infinitely is a little hand-wavy, but should suffice as a demo for middle and high schoolers.

More formal proofs involve limits that one wouldn't normally encounter until a course in real analysis.

Wikipedia has a whole page devoted to the topic: http://en.wikipedia.org/wiki/0.999...