## Sunday, September 16, 2012

### How far is Sacramento from Austin?

Distance and Midpoint Formulas (yawn)
How far is Sacramento from Austin?

Link to this in the INB content repository I added to msmathwiki

This week I move into Distance and Midpoint formulas and wanted to have better examples than the ones in the book.  I made a SmartBoard Notebook file that helps me walk through using the formulas step by step by trying to find the distance between the two cities.  This isn't much different than the book examples except for the fact that using technology we build to the conclusion step by step.

Where are the cities on the map? (you're welcome Social Studies teachers)
How do I plot points on a map?

What does the scale mean?  How do I use it?  How else could I find the distance between these cities?

Use the grid to plot the points then remove the grid because we really don't need it anymore.  I talk about how I can put the whole map in the first quadrant to make all of the values positive if I wanted to.  In fact, I can put it anywhere.  The important fact is the relationship is the relationship between the two points.  I could move the grid and do a second example if needed.

We work through the example by plugging in the x and y values to get an approximate distance of 1,458 miles.
Since GOOGLE is the shizzle to my kids, I justify the answer online.  We're pretty close.

I also have large wall maps that are dry erase so will have the students work in groups to work out other distances and midpoints.  I really got those just to add color to that wall, but hey, a little geography in math class never hurt anyone! (I have little globes too, from my pre-calc class two tears ago)

You can see my group sized white boards in the lower center of this picture.  They are in their home made white board stand I made out of PVC pipe.  I have 12 boards there!
If you look in the back near the window, you can see the individual sized white boards in their stand.

#### 1 comment:

1. Nicely done! I will definitely use this when I get to distance formula in my Math 2 class. Thanks for sharing!
--Lisa