I just finished sitting through a one hour presentation on using google earth in the classroom. Although it was mostly focused on Social Studies and English topics, I discovered some nice uses for the math classrooms.
I was impressed by what I saw including the measurement tool and the historical photos to see change. I loved the way I could look at so many different views of the same place. So some of the ideas I came up with for the math class.
1. Using a topographic overlay of say mountains or valleys, students can calculate the slope for parts of the mountains.
2. Using a map with a word problem so students see the actual route for a rate, time, distance problem to compare two different routes.
3. Calculate area of certain geometric shapes on the planet, for instance the NYC metro area. Students could easily look up the population and use the two pieces of info to find population density.
4. This lesson is designed for students to compare ski runs to find the most extreme and longest ski run. I think many kids would find this lots of fun, especially if into extreme skiing.
5. Use trig to figure out the height of something like a balcony out of Romeo and Juliet, a flag pole, something they can see in real life from the pictures. Many times you can find a well known building, you know the height and the distance, so you figure out the angle.
6. Look at the ways to get from point A to point B. Figure out the distance for each route and explain which is the best route. They could even figure out the % difference for each route and then rank the best routes.
7. Figure out the distance the balloons the Japanese released in World War Two, look up the time it took and then have students calculate the rate.
8. Use google earth to find the distance for several western trails used in the westward expansion, figure out the time it took to travel each trail and calculate the rate.
I see so many cross-curriculum uses for google earth and math. The above are just off the top of my head so now I'll just think about this and share a few more ideas when I get another list put together.