Math In Action - Construction (Part 1)

This episode of Math In Action features Bob Storar of Storar Construction discussing the mathematical concepts he uses on the job. In Part 1, Bob calculates area and volume so that he can determine how much concrete is needed to pour a foundation for a building. Students will measure, calculate area and volume given those measurements, and calculate the cost of pouring a concrete slab. (Youtube video here...links to download below).

Lesson Suggestion

One of the reasons I love this episode (and the concepts of area and volume) is that we can get the students to actually measure something instead of just handing them the measurements depending on how we deliver the problem.

I try and ease them into the math without them knowing that our conversation has anything to do with numbers or any concepts from our textbook. After talking a bit about how my daughter wants a basketball hoop for her birthday I tell them that I need to pour some cement for a court since the street is either too busy or has cars in front of the house. Then, I show them this pic of my house (all photos are clickable thumbnails), courtesy of Google Earth and the proposed court space in the backyard (please forgive my Photoshop skills...or lack thereof):

We agree that a 20' x 20' court is sufficient, and I start wondering if I have enough cash to do the project and the best way to get it done. Someone usually pipes up and says that they had a concrete truck at their house, and another student usually jumps in and touts the merits of do-it-yourself labor. We then start to compare the benefits of each:

First, DIY:

The students aren't just handed the information, but I wait until they get curious about a solution and ask the questions. Depending on how much access to tech you have, you can infuse some time on a computer, or you can Google information at their request, or just have it waiting for when they do request it. Either way, we find out that a bag of this concrete costs $4.98 at Lowe's.

A little calculation suggests that we are going to be buying a lot of bags of concrete and that doesn't even cover the cost of other materials and a healthy supply of donuts for nourishment. After deciding that the world is better off without me as a do-it-yourselfer we dug up a couple of quotes that we either found online or through a simple phone call:

Quote 1: $100 per yard.

Quote 2: $90 per yard plus $1 per square foot.

A couple of nice teachable moments that the students stumble into is how to calculate correctly the number of cubic feet in a cubic yard, and how to work with a depth of 6" when your other measurements are in feet.

Have fun with this and please let me know how you use these videos in class.

Links

The download link below is a link to an M4V file. You can also use Keepvid to rip it straight from Youtube, or Video Download Helper if you're a Firefox user.

Youtube Link:

http://www.youtube.com/watch?v=qxtOx2qL5jo

Download File Here:

http://www.mediafire.com/?qn1jzynmmzi