How did you modify this unit for use in your own classroom?: I have students with a range of abilities and learning styles. They were instructed to work in groups of 3-4. To help them succeed in this activity, I had double-sided counters and laptops available. The counters were red on one side (to indicate closed cells) and yellow (for open cells). These were placed in trays on each group's table. Laptops were available for anyone who asked. They were most often used to show the hundred cells opening and closing.

List your primary instructional objectives for your students.

What role did technology play in this curriculum unit?: I used a Smart Board and projector to introduce the problem via the PowerPoint presentation provided. The PowerPoint presentation can be found by clicking on "Lesson 3 - Prison Break Investigation, located at: http://teachnet-uk.org.uk/2007%20Projects/Maths-Algebra/Algebra/Algebra.htm Students who wanted to work on a laptops, using Microsoft Word, chose to simulate the grid in the PowerPoint. They constructed a 10x10 grid for each of the 100 cells. Some students used the same colors red (locked) and green (unlocked). Others wrote L or U for each cell numbered 1-100 as each guard went through and changed the letter as needed.

How did you assess and evaluate student performance?: Students were asked to first describe the problem in their own words to ensure that they understood the problem and what they were being asked to find. They then had to write down their thoughts as they progressed through the problem over a 3-4 day period.

Please tell us briefly about your background & teaching experience: Elaine Chin has been teaching 8th grade math with the NYCDOE for 6 years. During one of those years, she was a Math Coach. Prior to that, she was the Basic Education Coordinator for the Department of Youth and Community Development for the City of New York. She conducted monthly workshops for Adult Literacy teachers. Before that, Ms. Chin was the Education Facilitator for the San Francisco Conservation Corps for four years and two years at two other corps doing youth development. She entered teaching via the New York City Teaching Fellows program. Educationally, Ms. Chin received her BA in Sociology at Barnard College and an MA in Education at St. John's University. Ms. Chin completed a second MA in Math Leadership and her Building Leader Certification to become an Assistant Principal.

What are your recommendations for other teachers interested in adapting this unit?: I strongly recommend that students be given ample time to solve this problem. Trying to get it done in one day, even during a double period, does not do the problem justice nor does it give students the opportunity to truly appreciate the richness of this problem. By stretching it out over a few days and scaffolding as little as possible, my classes really had to struggle with it. This made them work harder and look for shortcuts or alternative solutions. I recently asked them to reflect on the most memorable activities, and many cited this one. Lastly, encourage as many different ways of solving as possible. It is amazing to see how an open ended problem can spark a child's imagination. I took a lot of pictures over the course of lesson and showed them in a slide show as students were struggling, around day 2. It was a nice break, and they were able to see other methods of solving. These can be used for my bulletin board, and my principal may use it as a backdrop for our graduation ceremony.

As an educator, I participated in a Math Leadership Institute. We were given this problem in a slightly different way. There were 100 lockers and 100 students. I thought about changing the prison cells to lockers to avoid the negative reference, but I then decided to leave it because it made the problem more interesting.