# Friday Five for September 9

The Friday Five spent the last two Fridays at the Minnesota State Fair, and wishes to thank Mr. Meyer for filling in last week. This week the Five is back in grand style with two puzzles, a study of the symmetry of functions, a Card Sort, and a Polygraph.

## Symmetry!!

Suzanne von Oy—who is becoming something of a regular in this space—brings us a lovely visualization of the symmetry of functions. Before the symbolic tests for even and odd functions, let’s recognize what we’re really talking about. Symmetry!! helps students do just that.

## Twin Puzzles

Cathy Yenca—another frequent visitor here—offers up a new twist on standard puzzles. Fill in the operation and grouping symbols in an expression lacking them completely in order to make the equation true. But WATCH OUT! You’ll need to make sure those same symbols in those same places make a second expression true also! There are tricks and twists along the way. Enjoy.

## Pentomino Puzzles

If you still have brainpower remaining after Twin Puzzles, then Jon Orr is ready with something more for you. Pentomino puzzles lend themselves to some powerful algebraic justification. Dig in and get ready to generalize!

## Polygraph: Identifying 3D Figures

Kyrstin Scaliatine gives us a wonderful look at 3-D figures. This is exactly the sort of thing we built Polygraph for. Notice the similarities and differences; build vocabulary as you struggle to describe them.

## Card Sort: Linear Functions

Finally here’s a short, simple Card Sort. What features of these linear functions will your students notice? Have them tell you as they sort these tables, graphs, and equations; and as you debrief afterwards.

With that, Friday Five is out and off to pick some apples! Honeycrisp anyone?