A quick flip to the quadratics section in each of the six textbooks lying around here I find at least one problem about finding the width of some border. The concrete around a pool, the walkway around a garden, the frame around a picture, the border around a rug. I present to you the collage. […]

- Visual Patterns
- Math Talks
- 180 Days of Math at Mesa
- Between 2 Numbers
- Math Arguments 180
- Estimation 180
- Dan Meyer's 3-Act Math Tasks
- Andrew Stadel's 3-Act Math Tasks
- Robert Kaplinsky Lessons
- Nathan Kraft's Virtual Filing Cabinet
- Sam Shah's Virtual Filing Cabinet
- Mathalicious Lessons
- Math Munch
- Yummy Math Lessons
- Desmos Classroom Activities
- Graphing Stories
- Math Mistakes
- 101 Questions
- Would You Rather
- Open Middle
- Which One Doesn't Belong?
- Fractions Talk