As I have stated before, I predominately teach through inquiry and problem based learning especially in math. Rarely, if at all, will you find me lecturing, I just don't think kids want to hear me ramble or that they are really listening. Instead I try to facilitate discussion through activities, problems, projects and carefully planned questions. However, there are still some subject areas that I have trouble with, geometry is one of them. The reason I struggle with this is it's sometimes really hard to come up with a context or a problem that allows students to explore the concepts that you are teaching. Not only this, but there is a lot of vocabulary, or social constructs as I like to coin it, that students just need to learn (e.g. The name of a four sided shape is a quadrilateral). Moving to primary has allowed me to shift my thinking nd find more ways to explore these concepts. I have had to revisit many of my favourite resources, like VanDeWalle, Marilyn Burns and Fosnot. VanDeWalle has an amazing learning progression for geometry in his book.
Here are some of my activities:
1) concept attainment: yes and no categories
For this activity, I had a bunch of 3D figures or shapes for students to see. I placed one object in the yes and then another in the no. I would then have the students discuss what they think is happening. I would then place another object in the yes and no category. Once this was done we would discuss and then I sent them off to try and figure out my rule or concept I was trying to get them to see. This was great for teaching terms like parallel, shape names (quadrilateral, triangle, prism, pyramid), etcetera.
2) 4 triangle problem:
This problem is in numerous resources but I found it in Mariyln Burns book. For this problem, I gave my students four equilateral triangles and told them they had to make as many different shapes as possible. They then had to organize there shapes. This was really good for teaching shape names and other various properties.
3) property hunt:
This activity is one that I traditionally do as it lends itself to exploring the various shapes and figures. For this activity I have the shapes or figures out and the students just try to find as many properties as they can. Normally, I would tell my students what properties they would be looking for or at least brain storm ideas from them. However, this year I just let them search. This often would generate lots of questions, which I would then stop the class and have mini congresses ( debriefing). This would then lead to more questions, exploration and so on. This change has really opened up my students understanding and has helped me see what the students actually understand versus what they have absorbed.
4) Make a figure:
This particular activity is used for 3D figures but possibly could be modified for 2D shapes. For this activity I gave my students various shapes and asked them to find what figure they made. This actually generated some really cool discussions around prisms an d pyramids.
For me inquiry is the best way of teaching but it does have some problems here or there. I hope that these are useful ideas. If you have any great lessons you love, please share; would love to hear them.