Explore this graph

Des-blog

Recent Posts

Friday Fave for July 13

A while back, we were very proud of our system for placing labels. “Works every time!” we trumpeted on our blog. We are still proud of this system, and it works every time if you’re using labels in the ways we had in mind back then.

But our users were determined to use labels in new and innovative ways for which that system didn’t work very well at all. Sometimes when you’re making a graph, you want to put a label in a particular place and not have it budge.

Now you can.

Once you have a label, you can click the wrench to adjust its location. You might want your label to the left, or the right, or above the point. You can do that, and you can change its size while you’re in there.

That’s what makes new, improved label placement this week’s Friday Fave.

Now here are a few activities that make use of labels…

Click Battle

Sugar Sugar

Predicting Movie Ticket Prices

Integer Game

Friday Fave for June 29

This week’s Friday Fave is a feature in Desmos Geometry: Transformations.

In order to appreciate the transformations tools, you’ll need to think of a transformation as a function. A function has inputs and outputs, where the set of all possible inputs is the domain, and the set of all possible outputs is the range.

Functions come in families. If you’re thinking about algebra, you can talk about quadratic functions in general, but to find an output for a given input, you’ll need to specify which quadratic function you’re using—perhaps by specifying coefficients for your squared, linear, and constant terms.

That’s how transformations work in Desmos Geometry. Say you want to reflect a triangle. You’ll first need to specify the reflection, you’ll need to specify a line. Once you’ve defined the reflection, geometric objects are your domain. Select anything you’ve constructed, and apply the transformation to see its output.

Rotations work the same way. Specifying a rotation requires two things: a point around which to rotate, and a degree measure for the rotation. If you apply the transformation more than once, each output becomes the next input.

Once you’ve begun thinking about transformations as functions, you may find yourself using these simple objects to make complicated and beautiful things, such as those below (click through on each heading to get to a version you can play with). That’s what makes Desmos Geometry transformations this week’s Friday Fave.

Square tiling

Kaleidoscope

Triangle tessellation

Hexagons

While you’re thinking about transformations, here are some terrific activities using transformations in geometry and algebra.

Transformation Golf: Rigid Motions

Marbleslides: Periodics

Function Transformations: Practice with Symbols

Card Sort: Transformations

Friday Fave for June 22

The Friday Fave is thinking about sequels this week.

Michael Fenton spoke about sequels a while back, and you should hear what he has to say on the matter.

https://www.youtube.com/watch?v=IreYFX6d3bg

Michael’s sequels are additional questions about a context within a lesson. And it is also worth thinking about when the next lesson ought to be a sequel to the current one.

Consider the case of Polygraph: Lines. Students play an engaging game that requires them to notice and discuss features of graphed lines for which they may not yet have words. As teacher, you introduce some of those words as the game moves along. But even if you don’t play Polygraph again, the game itself has created a rich space for asking additional questions, and for moving students further along in their mathematical journeys.

That’s where Polygraph: Lines, Part 2 comes in. In this sequel to the original Polygraph, students encounter increasing, decreasing, steepness, and intercepts in the context of thinking about situations that could arise in playing Polygraph.

Students sketch, write, and see each others’ responses in the service of better understanding the algebra of lines. All of it made possible by the original context of Polygraph. That’s what makes Polygraph: Lines, Part 2 this week’s Friday Fave.

And here are two more activities with sequels:

Polygraph: Hexagons and Polygraph: Hexagons, Part 2

Function Carnival and Function Carnival, Part 2