I’ve been working on adapting the Desmos activity “Racing Dots!” and finally got to use it with my class yesterday. We are only about 1/2 way through, but it is going very well! It really feels like it hit the mark of giving kids the headache for which the math will be the aspirin (to paraphrase Dy/Dan). Thank you to all the Desmos nerds for building such a wonderful tool. Thanks also to Richard Hung for great feedback and suggestions via the CL forum.
Here is a link to my current version.
Please share back any ideas, suggestions, questions…
Here is a new version of the activity after I used it with my class. I included a write up of the discussion we had after the activity where we co-developed a nice approach for using algebra to solve a system of two linear equations.