All the cards are moveable, so students drag the equations and graphs around to match them up. When they pair them up, they'll show up like this:
They keep moving the cards around until they get all the cards matched up.
But the best part (in my opinion) is the teacher view while they're working! I am kicking myself for taking so long to discover this. Teachers can see student progress as they're working! It will highlight correct matches in green and incorrect matches in red. Such an easy way to see which students need help as they're working!
You can even hit the "Anonymize" button if you want to display this up front for the whole class to see. Desmos also lets you see an overview of which cards students are getting wrong so it's easy for you to address some common misconceptions students are having.
It's so easy to share the activity with students when you're ready for them to try it. You hit the "Create Class Code" button (you'll want to create separate codes for each class period).
After you create the code, you'll get a screen like the one below that you can display for students or share the link with them in Google Classroom, Moodle, etc. They can create their own Desmos accounts if you want or they can do the activity without signing in (it just has them type in their name before they start).
Just an FYI, you can use the code you see above to test it out but the results will show up in my Desmos account, not yours. You'll want to grab the link below and make a copy of the activity in your own Desmos account so you can see your student results.
Click the button below to try the activity for yourself!