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## Monday, September 14, 2009

### Powers of 10 viewers

Today the 7th graders had a single period of math, just enough time to do a fun intro activity to our Power of 10 unit.

Last week, they had made "viewers" that were basically 10 cm base square pyramids with the top cut off. The height from base to top was 10 cm. This morning they went out to the greentop with meter sticks, notebooks and pyramids to find several different sized squares marked off with masking tape (.5 meters, 1 meter, 1.5 meters and 2 meters).

Their task was to find how high above the square they need to position the viewer to encompass the entire area of the square. They collect data in their tables and then examined them to find a pattern.

What's the point?

1. There is an algebraic relationship: side length of square is the same as height above the square
2. There is an element of practice with measurement units, particularly centimeters and inches
3. There is the nature of data collection in a table, number sense with measurements, and rounding to make sense of data.

Overall, a very successful activity.