## Exchange Rates

Posted: January 18, 2011 in Uncategorized
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Talking about proportions in my Pre-Pre-Algebra class (called Integrated Math).   We got on the topic of exchange rates.  A student asked how you can make money through exchange rates.   I’m a big fan of these Google graphs.  Lots of questions to ask.   We assumed we invested \$1000 in Euros and exchanged them again to see if we made profits.  Lots of questions you can explore here…. also a very scalable problem for higher classes.

## Metrodome Collapses

Posted: December 17, 2010 in Uncategorized
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River Falls got around 20 inches of snow over the weekend and it caused some havoc in our area.  The most popular story being the Metrodome’s roof collapsing.   Here is the video:

The student’s came up with a quick list of questions:

… The best question being  “Why did Brett do it?”.   Just Kidding.  The real question we wanted to pursue was “How much weight did the snow put on the roof?”.  I printed off a few resources for the students to use as they came up with their estimations:

The Storm
Metrodome Statistics
Snow to Liquid
Weight of Water

Our Solution

Our estimate was  about 3,852,429.412 pounds.

Varying the snow density

Let d = the number of inches of snow it takes to make one inch of water

$w = \frac{17 in}{d} \cdot \frac{1ft}{12in} \cdot \frac{435600ft^2 }{1} \cdot \frac{62.42796 lbs}{1 ft^3}$

$w = \frac{38524294.12}{d}$

More questions to consider

– How was the snow distributed on the dome?

– What type of shape is the roof?

– What was the exact snow to water ratio?

– How does temperature relate to snow density?

Conclusion

I like this video because it’s relevant, fun to watch, and stirs up a lot of questions.  I think we just scratched the surface on some of the math you could do with this video.    We covered: conversions, volume, area, estimation, ratios, density, rational functions.  I think this would also work great in a geometry class or lower.