### Playing with Desmos

Today seemed to be Desmos day in my building!
I planned to use it in all of my classes (more on that in a bit), but before school my across-the-hall neighbor stopped by to ask a question about using an activity in class. Then during first period, a colleague down the hall dropped in to ask about how to restrict the domain on a calculator screen, and a friend at lunch said she'd been creating activities to use in her classes.  Crazy!

My Honors Precalc students were working on an activity I'd created a couple of years ago based on a paper assignment that I'd used for years. I gave them the data representing Cincinnati's average daily high temperatures and asked them to fit a sine or cosine equation to it. Then they choose another city and do the same.  In the past so much time was taken drawing a graph that students couldn't even complete one city in class, let alone two!  And the instant check of the equation is so thought-provoking!  (Here's the activity if you'd like to check it out.)

In my Math 3 classes, we've been working through systems of equations. We took a week or so to solve algebraically (substitution, elimination, and graphing) and this week to read through word problems, create our own equations, and solve however. I've encouraged the use of Desmos but haven't required it.

Today I gave them a set of 4 problems and had them go through the process through Desmos. I'd already set up the activity so students would define their variables, enter their equations, and the activity would automatically show their graph so they could find the solution.  I went through it beforehand using the name "Answer Key" so I could compare their answers to the correct one.  That's how I ran it for my first period class.

 Message to students
 Checkmark for dashboard
And then I remembered that there was a way to use the Computation Layer to finagle the Teacher Dashboard so a student's correct answer would show up as a checkmark. My son's math teacher had sent me an email after this summer's Southwest Ohio Desmos Institute saying she'd figured out how to do it, so I did some quick editing during second period. (Thanks Carla!)  I didn't perfect it before my 3rd period class, but I did get it set so the students would get a message if they entered the correct equations, which they really seemed to appreciate.  Here's that activity if you'd like a look under the hood.

I don't consider myself any good with the computation layer, but I'm good at finding what I want in other peoples' activities and adapting to my own.  And I ask a lot of questions!

So many thanks to everyone who has helped me make my activities better!

Update:
A response from Eli:

What other company will immediately respond with such great help?! Another reason to love Desmos!