CATCHING FIRE: Ms. Mandy Bellm, Minnesota middle school math teacher, blogger and author of some sizzling math lessons. (Check out her latest on number systems on TeachersPayTeachers.) We loved her fierce defense of turning math into a survival game by letting "Barbie" (and "Ken") bungee jump off a school. (The math lesson? "The big idea, or essential skill, is to look for patterns in the distance that Barbie falls, compared to the number of rubber bands tied to her feet, and to use that information to predict much larger scales of bungee drops than could ever be simulated in the classroom," Ms. Bellm writes. "Students achieve an enormous sense of accomplishment when they can use the information to make predictions, and then test and confirm their results.") Ms. Bellm has been trying out "flex grouping" this year, with a team of open and communicative colleagues. So far, so good, she reports: "...having embraced the data, and used it for GOOD, versus EVIL, and as a TOOL, I have found many benefits to seek out the greater good, in the long run, than any evil repercussions resulting from 'over-testing.'"