Spontaneity

Yesterday, a very able set were reviewing different types of quadrilaterals. This is usually covered pretty well in primary school, so a few years on I expected the review to take about 10 minutes. I always start this topic by giving the students a bunch of little cards with quadrilaterals on them, and asking them to sort them into groups however they want. It makes the categorisation come out of concrete examples, rather than being some names put on the shapes by a teacher. It makes them think about the properties and argue about them, and it's the only way I've ever had kids remember this topic.

However, NOBODY came up with parallelograms, trapezia and rhombi. After discussion (which took a while; there were some great groupings, and it's a good review of shape properties) I asked them to sort them into ones with 2 pairs of parallel lines and ones with one, but they still weren't using any names. So we played hangman! We finally get to trapezium, and they all said 'Ooooooooh, yes, we remember that word! But aren't they really complicated?'

Of course, it isn't, and they'd already sorted the shapes - with the classification coming describing the groups of shapes. They were soon happy with the definitions, but it appeared that they were confused with how the classifications related to each other. We were now totally off the lesson plan, and I knew they needed something else to reinforce the concepts and the relationships between them.


I remembered a fantastic idea I was introduced to last year, but didn't use. I got them to clear their desks apart from the shapes, gave each pair a whiteboard pen and told them to draw as large a circle as possible on their desks - board marker comes right off. They went wild. We drew a huge Venn diagram on their desks and they sorted the shapes into it, then added new ones. They were extending the diagram, talking about the relationships, discussing where the square and rectangle fitted, and generally squealing about drawing on the desks.

After 20 minutes, they sketched it into their books and as they packed away, one girl asked if she could take a photo on her phone. They were soon all snapping pictures, and I told them this was my new criteria for a successful lesson - so good the kids want to take a photo of it!