# Friday Five for March 18

The Friday Five is still wearing its Desmos green after a busy week of celebrating π, basketball, and shamrocks. We’ve got algebra activities galore this week. Cereal, hoops, fencing, and pure graphing joy form the bases for the latest Activity Builder activities for your classroom. Click through and get a head start on next week’s lesson planning!

## Building Polynomials #1 – Parabolas

What happens when you multiply a line by a line? That’s the question at the heart of this activity from Jamie. The answer is parabolas, and the activity has algebra students exploring the results of this way of thinking.

## Sugar, Sugar

Jon Orr, whose work we have featured in this space before, brings us an exploration of the relative sugar content of five cereals. The question Which one of five given cereals is most sugary? yields to a well-ordering of the cereals by sugar content per serving, and then to an algebraic representation of this information. Students apply their thinking to additional cereals and to sodapop. You’ll never look at nutrition labels in quite the same way again.

## Build a Bigger Field

The Desmos Teaching Faculty has Des-mified the fencing problem. If you’ve ever taught anything from Algebra I through Calculus, you’ve encountered the question of How do I get the biggest possible area in a rectangular field enclosed by a fixed length of fencing? Now you can see what Activity Builder can bring to these proceedings. By all means, feel free to duplicate and tweak to make it just right for the level you’re teaching this semester.

## Will It Hit the Hoop?

It’s madness in this classic from the mathtwitterblogosphere (#mtbos) archives. More than five years ago, Dan Meyer asked What Can You Do with This? about a series of carefully framed videos and stills of basketball shots. Now it’s on Desmos. Algebra 1 or Algebra 2 students will enjoy making, then checking, their predictions.

## Graphing Linear Inequalities

Finally, Tom Keller has a challenge for your Algebra 1 students: Write inequalities that include the blue points, exclude the orange ones, and are bounded by lines through the black ones. Simple premise; fun challenges.