Dr. Peter Liljedahl, a professor of mathematics education at Simon Fraser University in Vancouver, Canada, and a former high school mathematics teacher, is known worldwide for his 2020 book, Building Thinking Classrooms in Mathematics: 14 Teaching Practices for Enhanced Learning.

In his groundbreaking approach, activities are designed to help teachers emphasize mathematical thinking and student engagement in their lessons, as a pathway to deeper learning.

HSFI's Jeanne Klepacki and Rachel Goldstein, 9th grade Algebra team teachers, decided to incorporate one of these activities in a recent class.

In a Statistics Review Lesson on "Box and Whisker" plots, students worked in randomly selected groups to create a set of exactly 10 numbers that satisfy 4 conditions:

1. The MEAN had to be greater than the MEDIAN

2. The MEDIAN had to equal 6

3. The RANGE had to equal 8

4. The IQR had to equal 5

"What made it especially interesting was that there were so many different ways to approach it," Ms. Klepacki explained. "Some groups decided to start by figuring out how to guarantee a median of 6, while others started by establishing a range of 8 and built from there. They kept adjusting their numbers, recalculating, and discussing how changing one value could affect several statistics at once."

What were the results?

Ms. Goldstein said, "There wasn't one correct data set, so different groups ended up with different answers and approaches. That really got them invested in the process.  It led to some great mathematical conversations, as they compared strategies and defended why their solutions worked."