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This search engine searches all of the sites below to quickly help you find a problem-based lesson (also called 3-Act Task, mathematical modeling, or application problem):

The links below are the pages that are being searched by the search engine:

There must be many great sources of lessons that I am missing.  Please leave me a comment to let me know which websites I need to add to the search engine.

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  1. Wow! This is amazing! Thank you so much for doing this. One other great site I’ve found is It has some very cool project ideas, similar to Mathalicious but not as detailed. Keep up the great work!


    • Thank you Ed. I actually added to the search engine but forgot to add it to the list of sites on this page so thanks for the heads up.

    • Hi Teresa. Glad it is useful. I searched around but couldn’t find anything like a problem-based lesson. Could you give me a specific link to a lesson to check out?

  2. Hi Jennifer. There are some cool lessons there but I don’t know if they would fall under the category of problem based lessons I am aspiring to capture here. Thanks for your idea!

    • Hi Shaun. Check out Google’s Custom Search at That is where you can create your own search engine. It is rather robust but not perfect. For example, it is very challenging to include a site but exclude the blog posts.

      Regarding your suggestions, those are all great sites but Graphing Stories and Fawn’s awesome blog are not really within the problem-based learning domain so that is why I haven’t included them. That being said, both of them have been links on the right side of my blog for quite some time so I definitely value them both.

      I am having trouble getting the Barbie Bungee jump to load but I will try again another time to check it out.

  3. Have you checked out the website:

    He has some pretty useful articles, especially on strategies for formative assessment.

    Full disclosure:
    He’s a colleague of mine so I am biased, but I do get a lot out of what he shares and apply to my own work.

    • Thanks Blue. David is great but I don’t believe he is creating any problem-based lessons. If he is, please list a link to where I can find them.

    • Hello. To me the answer is both yes and no. Clearly these are problems that you can base a lesson around. However they are not of the style that we are including in this search engine. If you are interested in examples of elementary tasks of this style, check out Graham Fletcher’s problems here:

  4. I was so excited to find this resource that I immediately emailed all of the teachers in my department a link to this post. Then, I realized that I had a double block of Algebra I approaching in 15 minutes and I could use this search tool to find a resource that might raise the engagement level for my students. Sure enough…I typed “graphing quadratic equations” into the search box, and numerous resources appeared. I selected the second hit on “Angry Birds”,and it fit seamlessly into my lesson plan. The students asked such great questions and were able to clearly answer questions about the vertex, x-intercepts, and orientation of the quadratic equations that modeled the paths of the angry bird. Of course, then I had to send out another email to my department ranting and raving about my math rush.

    Thank you!

    • Hi Alex. Obviously I love Open Middle, but it doesn’t seem to be a good fit here. This search engine is more for math modeling problems also known as 3-Act Tasks or problem-based lessons. What do you think?

  5. Hi Robert,
    I will be sharing this with my colleagues at school that focus on the Math contents…
    Thanks for a great resource on behalf of all those teacher who need a little more help in the topics area.

    • Hi Ben. I haven’t heard of this but it seems like there are some useful problems there. I’ll add it to the list. Much appreciated!

  6. I LOVE THIS! I’m so excited to have a search engine that will only search for mathematical tasks! I’m sharing it with everyone I know:). Thank you so much, Robert!!

  7. Hi Robert. I love that you did this. It makes it easier to get teachers to try these out. I also have another site – He has developed some tasks using the 3-Act format.

    • Can you explain more about what you mean to “embed this link”? You can put a link to this blog post on your own site, that’s no problem.

  8. Hey! I think this is a great list of resources and so thankful for the list. It has saved me in the last a lot. I am in my grad school class and researching on PBL. I am a little confused how this qualifies has PBL and not just projects or really good math lessons. My research suggests that with PBL the learning is happening through the project and the project is not a activity we tack on at the end. I also read, “While the learning context is common to all groups, the paths may differ considerably—all leading to distinct learning. In project-based learning all students engage in a common project with unclear processes but clearly identified expected outcomes.” Can you speak a little bit about your thoughts on PBL. I am trying to find some math teachers I look up to and follow to help me learn about PBL in a secondary classroom. Please respond or email me at [email protected]

    • Hi Virginia. Thanks for this question. I should be clear that this is a PROBLEM-based search engine and not a PROJECT-based search engine. While the two have similarities, it sounds like you are talking about project based lessons and not what I am focusing on.

      I don’t do a lot with project based learning so unfortunately I’m not a good resource for you there. Sorry! If you want to learn more about problem based learning, you can read more here:

    • Thanks Merryl. I’m not aware of any problems that Youcubed has that would be considered problem-based lessons like 3-act tasks and the ones on my site. If you can point me in the right direction, I’d love to check them out.

    • Hi Danielle. I understand where you’re coming from, but that isn’t a problem for me. You often get what you pay for, and as much as it feels nice to get lessons for free, the Mathalicious team’s full time job is creating high quality lessons for educators. They deserve to be compensated.

      Personally, I prefer to be aware of what’s out there so that I can choose what’s best from me. Sometimes it will be worth paying for.

    • Thanks Sarah. I think this issue is stems from the word “problem” being so broad. Yes, I have looked at those problems, but they aren’t like the 3-act tasks and other problem-based lessons I am looking for with this search engine. I want problems that are more like these: