## Tuesday 24 March 2015

### MFM2P - Day 30 (Spaghetti Bridges)

Tuesday means Estimation 180 for our warm up. We did a belated St. Patrick's day one:

The estimates were good and all between 31 and 50. This tied in nicely with the volume of a cylinder work we have been doing. I like that you can see the layers inside the glass.

My students then spent a little time working through some surface area of prisms and cylinder questions. They had to do some unit conversions along the way. I like to incorporate these where it makes sense along the way, not do conversions for the sake of doing conversions (they are in the 2P curriculum).

Next, spaghetti bridges. I actually chose to use spaghettini instead as it breaks a little more easily. Spaghetti is remarkably strong! Students were randomly grouped into teams of three. They made "bridges" by holding the ends of the spaghettini through which they had threaded a small Dixie cup. I had already holepunched the cups for them.

They started with 1 piece of spaghettini and added pennies to the cup until the spaghettini broke. They recorded the number of pennies then started again with 2 pieces of spaghettini, and so on. They stopped when they could no longer add pennies to the cup. I loved hearing them sharing how many pennies they got for a particular number of spaghettini. By sharing I do mean shouting across the room, but when they are shouting about the math activity they are working on, that's okay!

Once they have collected their data they plot it by hand first and then using a graphing calculator. It's not the "cleanest" data so they will likely use the calculators to get the equation of the line of best fit. They didn't get that far today, so they will continue tomorrow.

I would strongly recommend that you have a broom in the room if you do this activity as it gets a little messy with broken spaghettini all over the floor. In my experience some students like to sweep up and are more than happy to pitch in.

Here are the handouts: spaghetti bridges, spaghettini bridges and the extension with credit to Alex Overwijk.

To be continued tomorrow...