helping granddaughter with math homework

[--Pete]

Hi,

My 6th grade granddaughter has always and continues to struggle with math. It has always been a hole in my education as well. However, I did learn arithmatic and figured I ought to be able to help her from time to time. The other day she brought home a problem which was "express the mixed number 8 1/3 as a percent". My wife and I both immediately answered 8.33 percent which is what my granddaughter had answered. Apparently the correct answer was 833 percent. I remain confused as to what I am missing here. I must be assuming something not in the question. Anyway, I guess I cannot be counted on to be of much assistance to her. Also, her district uses the connected math curriculum which apparently eschews teaching kids to learn how to calculate things manually etc. Bah!

As to the teaching of math, in general, it is done very poorly. Many who teach it don't really understand it themselves. And what is taught is often the basics to become a mathematician rather than the general knowledge (and ability) needed by the average person.

The specific problem you lay out hinges on the definition of 'percent'. It comes from the Latin, and can be translated as 'parts per hundred'. So, 1 percent (1%) is one part in a hundred or 1/100 or 0.01. A 100 percent is 100 parts per hundred, or 100/100 or 1.

Now, since 100% is the same as 1, then 8 is the same as 800% by simple ratio. Then 1/3 is (approximately) 33/100 and so 8 1/3 is 833% (more correctly, since 1/3 is a repeating decimal, it is 833.33...%)

Hope that helped.

--Pete