Since we're celebrating round things (see Happy Pi Day, http://ireport.cnn.com/ir-topic-stories.jspa?topicId=570032) on CNN,  and as our little ones slough towards their standardized tests and whatever other contrived remnants of “No Child Left Behind” validation we foist upon them at this time of year, perhaps someone could reflect on their time in grade school and answer a few simple questions over which our students will grind their No. 2 pencils into oblivion. Simple 6^th Grade math: the conversion of fractions to decimals to percents.

Sixth grade, that time in one’s scholastic life that 90% of us shut down on mathematics. Oops, there’s one of those percentages that we like to fling about so recklessly, again. “Percents” – we see them everywhere: shopping, banking, taxes, and sports. They are intricately and seamlessly – and thoughtlessly – woven into the very fabric of our everyday lives. And we only pay attention to them if they’re going to get us a discount on our next purchase or a better return on investment.

Percent is based on the concept of “the whole”, “one”; completeness. The word comes from Medieval Latin, per centum – by the hundred. So, when it’s all there we say “100%”, and we often use circles to demonstrate this concept since they embody this perception of wholeness, especially in the context of learning for young minds. We label the circle “one whole” or just “one”, which is the same as 100% – meaning it’s all there. Then we dutifully go about breaking it up to demonstrate parts of the whole: the dreaded fractions and percents.

When we break that whole up into quarters, ¼, .25, or 25% everything works out quite nicely – it all still adds back up to 1 or 100%. But a funny thing happens on the way to the bank, quite literally, when we break that whole up into thirds: once the conversion is made to decimals and percents, something is lost. Why is that? Where did it go? How did we start with a “whole” and end up with less than that? Why are we so willing to accept this error as “OK”?

We hammer our children for laser-point accuracy on these standardized tests, but then we are willing to slough over an error like this with nary an explanation? “Eh, just round up.” We’ve been doing it for hundreds of years. I guess that makes it OK.

Not important? Insignificant?

One last set of questions for those who stayed to the end of class:

I wonder why just about everything we purchase is priced .99? We don’t even notice that the exorbitant price we pay for gas has an additional .009 tagged on the end of its price per gallon. Ever wonder why? Why don’t the merchants just price these commodities at an even dollar amount? It’s not “buying psychology”, because “9’s” look bigger than “0’s” and we all round up anyway. Ever look at your credit card and billing statements to notice that everything is calculated in odd percentages? Who keeps these little leftover “missing pieces”?

Ever hear the saying “the rich get richer by counting their pennies”?

And keeping yours.  

here's another take from an older posting:

http://ireport.cnn.com/docs/DOC-315523