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## Wednesday, February 12, 2014

### How Thin Can You Slice Your Pi?

3.1415926535897932384626433832795

That is the value of 

Students should use the π symbol and its corresponding value when applicable on the Regents Exams in Algebra I, Geometry, and Algebra II (Common Core). The approximate values of π, such as 3.1416, 3.14 or 227 , are unacceptable unless otherwise specified.

The statement above is from NYSED's document

What could possibly be "its corresponding value"?  Mathematicians throughout the world know that π is a transcendental number (worse than irrational, to the uninitiated). If the state's guidance wants to use an exact value in any place-value system, it is asking for the impossible. If it saying that the π button on a calculator must be used, it is just accepting the calculator's approximation as "better" than any others.

Before anyone passes judgment on my comments, I suggest that first read a column from the July 21, 2012 at Scientific American entitled "How Much Pi Do You Need?" (get it here).

Another good read is a page from BetterExplained.com  by entitled Learning Calculus: Overcoming Our Artificial Need for Precision (see it here) which says
...approximations are a part of Nature, yet everything works out. Why? We only need to be accurate within our scale. Uncertainty at the atomic level doesn’t matter when you’re dealing with human-sized objects.