I absolutely love Geogebra, I use it in nearly every lesson to the extent that I’m not sure how I would teach certain topics without it!

I’ve written before about the power of starting from a blank sheet (angles in parallel lines, trigonometry, circle theorems), but recently I have found and used some excellent visualisations that other users have created and kindly uploaded. I feel like this aspect of Geogebra has improved considerably over the last couple of years in particular the search. I often have an idea in my head for what I want to show students and within a few seconds I have found exactly what I need by searching. Using dynamic geometry that you can narrate to (or not) is so much better than just playing a YouTube video. I try to think of points where I can ask “what will happen if…” type questions.

Here are my latest finds that I have used in class recently. Click on them to take you directly to the Geogebra. I’m sure this collection will be added to as I find more.

The idea of these tasks is to get students to think more deeply about volume and to help visualise how different volumes “fit” together.

Questions 1-5 can be done by effectively counting cubes. Multilink cubes would be good to help with the visualisation at this point.

Question 6 is the one to get the discussion going. Is the answer 16 (if you picture them as solid cubes, rounding down) or 21.12 if you consider it as a flexible volume (e.g. a liquid)?

If you want to adapt this resource you can create your cuboids using this Geogebra resource.

## Ideas for better maths teaching