Introduced volume to year 7 supp class today as part of our measurement unit.

We began with an image on screen similar to this one, using the ‘delete the textbook’ method to generate some questions/discussion:

One of the students knew the term ‘rectangular prism’ but we talked about size issues, definitions, guessed measurements once we knew some etc.

After that I used one of my own ‘estimation 180’ type pictures:

So – here was a rectangular prism… how many of the cubes would fill it? Everyone had their best guess/highest/lowest etc. and were then hooked in when I presented them with a bucket full of 1cm cubes they had to start filling the box and count.

Turns out their estimations were way under! (For future reference…dimensions were 5 x 5 x 12 = 300!) Next I pulled out a bit bigger box, then an even bigger one… it had probably taken 15 minutes to work out how many cubes fit in the small box, so how long would it take to work these other ones out?!? At this point I was able to bait them with saying there was a 15 second solution! And it would be around 15 seconds for each of the boxes!! (ie. volume formula)

I showed them the formula and before we could practice too many ‘normal’ volume questions, our lesson was up. We’ll leave that for tomorrow…

Once extended further, can look at things like Popcorn Picker (volume of cylinder)

Another idea from Robert Kaplinsky was calculating volume based on a drug bust! The content might intrigue, the lesson looks a bit long for its output??