# Day 10: Crossing The River

Today in Algebra, students started with Estimation180. We have been slowly working our way through the first three days, then this happened:

After students worked through Crossing The River which is out of Mark Droscoll’s Fostering Algebraic Thinking.

What steps do you find yourself repeating over and over and over and over?

For some reason I just can’t get enough of this problem, I have been using it before I was a preservice teacher. The objective of the day was to introduce creating and solving two-step equations but students went well beyond my expectations. Here are some of the scaffolding questions I used to build up to our final equations.

Stretch student’s thinking; it is painful to draw out pictures for 100 adults. I told em the next question I was going to ask was 559 adults.

We talked about how Algebra makes our lives a whole lot easier.

But what does the equation mean…?

Has anyone ever seen an equation like this?

It has more than one solution… why’s that? Kinda weird.

I was too excited today to take pictures of student’s work, there were some awesome solution methods out there though! Tomorrow I am going to follow up with a quick review of two-step equations then some practice problems.

In Geometry students had a work day and practiced problems on various pairs of angles/angle addition postulate. They were cranking the problems out today. I like to give students one day a week to work through problem sets in class instead of assigning them as homework (more to come on how we do homework in a future post)!