Students will learn what polyominoes are, and see several puzzles involving them. Start by replicating the lesson shown here. Then replicate the lesson shown here and here. Next, give your students this challenge. After they've found all the pentominoes, have students identify the lines of symmetry and rotational symmetries of each pentomino. Further, which pentominos could be folded up into a lidless box? Finally, give your students the challenges found here, here, and here, in whatever order you please.
Note: This lesson should follow a lesson on using the mean.