Des-blog

It is January and the Friday Fave is C-O-L-D.

The Fave understands that Sunday’s predicted high of 20°F is not technically twice as warm as tomorrow’s predicted high of 10°F, nor five times as warm as the current 4°F, but it sure is going to feel like it.

Temperatures don’t really work proportionally (a fact that can be derived from the fact that 0°C is not the same as 0°F), but you know what does work proportionally?

A clicking robot!

This week’s Friday Fave is Click Battle, in which we challenge students to predict how many times they can click their mouse buttons in 10 seconds.

We give them a chance to practice for five seconds, and then to revise their predictions.

Are your students robots? Is their click rate consistent?

And if survival in the end times required having the fastest-clicking robot on your team (and it obviously will!) then which of these two robots should you pick? Why?

How will your students reason about this choice? The strategies they use to make these decisions are the real mathematics here. Do they compare 6 seconds to 4 seconds, which is 1.5 times as long? Do they use unit rates? If so, which unit rate: clicks per second, or seconds per click? Do they think about common multiples of 4 and 6, or of 38 and 23? Linger on your students’ strategies, and celebrate their creative ideas!

Now get those clicking fingers (and the brains they’re wired to) warmed up, and prepare for the Click Battle!

While you’re exploring the wonderful world of proportionality, here are a few other faves to try.

Tile Pile

Sugar Sugar

LEGO Prices

The Friday Fave is feeling nostalgic this holiday season, and is thinking back to the activity that started it all.

Desmos released Penny Circle a bit more than four years ago, in July 2013—our first activity. Penny Circle was well received by students, teachers, and curriculum aficionados alike. Embedding the Desmos graphing calculator into an online modeling activity that runs on any web browser, and supplementing it with tools for collecting and sharing data, and for teachers to see student work in real time gave teachers and students a new kind of mathematical power.

But the years did not treat the underlying technology kindly. Browsers evolved. Our ideas about how to use technology to support teachers’ work evolved.

All of which is why we’ve rebuilt Penny Circle using the Activity Builder platform. What originally took months to build took us a couple of weeks to rebuild from scratch inside of Activity Builder, a testament to the power of this platform.

So now is the time, fellow citizens of the math-learning internet! If you’ve not used Penny Circle before, it’s waiting for you here. If you used it a while back and it was showing its age technologically, try the updated form!

When your students are arguing over whether and why their data is linear, quadratic, or exponential you’ll be glad you did!

And while you’re thinking about modeling activities, here are a few more favorites the Fave recommends.

Charge!

Mocha Modeling: Starbucks Locations

Card Sort: Modeling

The Fave is feeling lucky, which is why Chance Experiments is this week’s Friday Fave.

Your students analyze a spinner, and they spin it virtually. But then they’ll design a spinner and test that out.

What does it mean for something to be “almost impossible” or “almost certain”? Does “almost impossible” differ from “unlikely”? How exactly? These are some of the big questions of probability and statistics–questions that Chance Encounters seeks to raise in your classroom.

And along the way, many other important questions will probably surface. How should I subdivide the spinner if I want to get exactly one red in 36 spins? Will a fair spinner always give 50% red? Will an unfair spinner ever give 50% red? Whether you are feeling lucky or not, these questions matter. Linger on them in your classroom.

And if spinners have you thinking about circles, here are three circle-based activities for you and your students.

Polygraph: Conics

Circle Patterns

Lawnmower Math