Dustin Purdy Blog

Oct 24, 2026 · @MrPurdyMath Today is October 24, 2026, written 10/24/26. Those three numbers are the side lengths of a right triangle, which makes today a Pythagorean Theorem Day. Soak it in, because it's the last one we'll get this century. The next one isn't until March 4, 2105. I love dates like this because they turn a calendar into a math prompt. Nobody has to be convinced that the date matters. It's right there at the top of every worksheet, every agenda slide and every phone lock screen. All we have to do is ask students to look at it differently. Check the math The Pythagorean Theorem says that in a right triangle, the squares of the two legs add up to the square of the hypotenuse. A date qualifies when month² + day² = year². 10^2 + 24^2 = 26^2 100 + 576 = 676 Picture a right triangle with a short leg of 10, a long leg of 24 and a slanted side of 26. Today's date is that triangle. This is a great moment to slow down with students. Before anyone reaches for ...

  Oct 18, 2026 · @MrPurdyMath Display a picture, like of a roll of cardboard on the board and ask, "What do you notice?" Within a minute, hands go up all over the room, including from students who rarely talk in math class. That's the power of Notice and Wonder: every student has something to say, and no answer is wrong. This routine comes from the National Council of Teachers of Mathematics (NCTM), whose Notice and Wonder lesson plans pair a striking photo with real math. Their cardboard lesson (grades 6–8) is a great example. Its first part works as a five-minute warm-up in almost any lesson. When you have more time, the second part turns it into a full lesson on circles and cylinders. The 4 steps Here's the whole warm-up, using NCTM's photo of a rolled-up sheet of corrugated cardboard. The sample responses come straight from the lesson. Look silently for one minute. Show the image and say, "Take a minute to carefully look over the image." No hands y...

On Friday, October 9, the Norwegian Nobel Committee awarded the 2026 Nobel Peace Prize to Navi Pillay. That got me thinking about the prize itself, and about how much a simple picture of its history could tell our students. So I made one. It's a grid of 126 dots. Most are filled. A few are empty. There's no title, no labels and no key. If you're anything like me, you love a graph that starts a conversation before anyone knows what it shows. That's the whole idea behind a slow reveal: students reason about the data first, then get the context a little at a time and revise their thinking as they go. This one takes about 40 minutes, and it works as a 10-minute warm-up if you're short on time. Reveal 1: Just the Dots Start with nothing but the dots. Give students a full minute of quiet think time before anyone talks, then ask the two best questions in math class: What do you notice? What do you wonder? Write down every idea without confirming or correcting it. Students ...

When I began my first year as an Amplify Desmos Math High School Professional Learning Specialist , I knew the experience would challenge me to grow as a facilitator and mathematics educator. What I did not fully anticipate was how much learning would happen before I my launch first session with teachers. This post has been a bit delayed, but I am excited to share my experience from year one as an Amplify PLS. Looking back, one of my biggest takeaways is that becoming an effective Professional Learning Specialist is not simply about knowing the curriculum or being comfortable presenting. It is about understanding the mathematics deeply, experiencing the curriculum as a learner, building relationships, engaging in intellectual prep , listening carefully, practicing, receiving feedback, and continually refining your craft. Although I ultimately delivered only one professional learning session during my first year, at the end of August , I grew tremendously throughout the experience. That...

  Oct 9, 2026 · @MrPurdyMath Monday, October 12, is Indigenous Peoples' Day. It's a day to honor the first peoples of this land: their histories, their cultures, and the communities that are still here and thriving today. For a lot of our students, it's also a day off with a name they've never really thought about. That's where we come in. When we take even ten minutes to recognize Indigenous peoples, we're telling students the truth about where they live, and we're showing them that Indigenous knowledge isn't just history. It's math, science, art and language that people are still using right now. If you're anything like me, you've wondered how to fit that into a math class. How do I teach land acknowledgment and explore Indigenous cultures without losing a day of instruction? Here's what I landed on: you don't have to choose. The math is already there. Maya mathematicians used zero centuries before Europe did. Lakota star quilts ar...

What languages are spoken in the United States? How does where you live influence the languages you are likely to hear? And what can data tell us about the communities around us? Nearly 1 in 4 people in the United States speak a language other than English at home. That statistic creates an opportunity to explore percentages, ratios, proportional reasoning, estimation, and data representation while connecting mathematics to language, identity, community, and belonging. I created “How does America say hello?” as a short 5–10 minute data talk using 2024 U.S. Census data to help students make those connections. Starting With Notice and Wonder The routine begins simply. On every slide, I ask: What do you notice? What do you wonder? Students have about 30 seconds to think independently and another 30 seconds to share with a partner. We then hear a few observations and questions before moving into the mathematical prompts. This sequencing is intentional. Rather than telling students what is ...

It’s that time of year again— conference season . One of my favorite parts of being an educator is the opportunity to step outside of my own classroom, connect with other educators, share ideas, and learn from the experiences of others. Conferences give us a chance to pause from the day-to-day demands of teaching and think about the bigger questions: How can we create better learning experiences for our students? How can we make mathematics more meaningful? How do we ensure every student sees themselves as a mathematician? This year, I’m excited to have the opportunity to present at NCSM, NCTM, AMTNYS, and AMTNYC . While the sessions have different focuses, there are some common threads running through all of them: student agency, meaningful mathematics, data literacy, equitable access, discourse, and creating learning experiences that center students as thinkers. NCSM: Data Stories for Justice At NCSM , I’ll be presenting Data Stories for Justice: Empowering K–12 Students to Investiga...