Des-blog

The Friday Fave doesn’t really understand running. The Fave runs fast, but only when chasing a Frisbee or ball. The Fave is a bit like a Labrador Retriever that way.

Nonetheless, the Fave understands that people do run when they are not chasing things, and that such people keep track of how far they have run and how long it has taken them. If you’re going to be doing such a thing, you really should be sharing the mathy results with the rest of us.

That’s exactly what’s going on in The Running Game, this week’s Friday Fave. The Running Game isn’t an elaborate affair; it’s a simple, clear activity that has students use proportionality to go from inaccurate guessing to very reasonable predicting.

So go ahead and give your students the experience of using math to do something better.

And then make them run laps. It’s the end of the year; there’s a lot of energy to burn off! Tell ‘em the Friday Fave said they had to.

And while you’re watching the clock, here are a few more activities that use time as a variable.

Water Line

Predicting Movie Ticket Prices

Commuting Times

The Friday Fave has a soft spot in its heart for fractions. Just because we CAN write things in decimals doesn’t mean we should.

Often, a fraction is the exactly right thing to express the relationship you’re investigating.

Case in point—finding areas of sectors of circles. This week’s Friday Fave is Sector Area, where you’ll have way more success expressing your responses in the form of a fraction. It’ll be more precise, and it’ll generalize better in the end.

And generalizing is what this is all about. Students don’t need a formula for sector area; they can figure this out for themselves. With Sector Area, we provide tools for doing exactly that.

And then while you’re in a circular kind of mood, consider taking these activities for a spin…

Circle Patterns

Polygraph: Circles and Ellipses

Penny Circle

Spring is a great season for symmetry. Flowers have mirror and rotational symmetry. Day lengths building up to the summer solstice are approximately symmetric to those that follow. On the first day of spring a plane through the equator splits the sun into two symmetric halves.

So it is that the Friday Fave is thinking about symmetry on this fine spring day in the northern hemisphere. (Sorry, Australia!)

In this case, it is the symmetry of functions. Suzanne von Oy—high school teacher and Desmos fellow—built the original and Desmos applied a tiny amount of polish to Symmetry.

This isn’t a high-production super-ambitious sort of thing. Its mission is simple—to give students a chance to train their eyes for two kinds of symmetry of functions.

And then it ends with a killer extension.

Simple set up; powerful thinking. That makes Symmetry a Friday Fave.

While you’re thinking about transforming functions, here are a few on that theme:

What’s My Transformation?

Polygraph: Transformations

Marbleslides: Parabolas