Hello, reader! If you intend to post a link to this blog on Twitter, be aware that for utterly mysterious reasons, Twitter thinks this blog is spam, and will prevent you from linking to it. Here's a workaround: change the .com in the address to .ca. I call it the "Maple Leaf Loophole." And thanks for sharing!

## Wednesday, September 30, 2015

### Exponential Functions and also Area of a Triangle

That title is confusing, right? I know! I just wanted to alert y'all to some tasks that recently went up on Illustrative Mathematics that might address some of your needs, if you are teaching these things.

Exponential Functions: These tasks involve negative exponents in a functional relationship in a context and are aligned with F-LE.
• Decaying Dice (It's like the penny lab for modeling half-life that kids often do in Earth Science... except with dice.)
• Predicting the Past (Making sense of negative integers in the domain of a simple exponential growth function.)
• All Your Base are Belong to Us (Exponential decay and negative exponents, together at last. Bonus points if you get the reference.)
• DDT-Cay (Interpreting the exponent in a half-life equation.)

Area: These are meant to be used to build understanding as you're working toward a formula for area of a triangle in sixth grade (6-G.1). But they could be useful to reactivate knowledge at the beginning of a study of area in a later Geometry course.
And, hey, it is non-trivial for me to test stuff out with kids these days, so if YOU try them out and you notice stuff or have suggestions, you can comment here or better yet, right on the task on the IM site. (Please let me know if you do that - I don't think I get a notification. And thanks!)

I did draft the initial versions but I can't take credit for these. Tasks published on IM are very much a team effort. Many thanks to Ashli Black who is an ace reviewer and helped me make these a ton better.