Area challenge

A long while since I last posted. The enthusiasm of the new year when I was sure that could post every week seems to have vanished into smoke a long while ago. I need to get back into the habit of posting more, especially as the class blog has died a bit of a death as well.

This week I had the dubious privilege of having the head of maths at the local secondary school visit to watch one of my maths lessons. This was a return visit as my colleague and I had gone to the high school to sit in on their lessons just before half term. I returned back to school horrified by having seen a maths lesson where the children sat in virtual silence for an entire lesson doing practice SATs questions…….in October.

I wanted to show a lesson where the children were all actively involved but learning at the same time and was pleased to read Mike Askew’s article on area and perimeter in this month’s Teach Primary. This fitted perfectly into our maths planning and was a brilliant lesson. I set them Mike’s challenge of drawing a shape with an area of 20 cm and measuring the perimeter and then trying to find 3 other shapes with the same area but greater perimeter. I began the lesson by giving them the statement  ‘If the area of a shape increases, then so does the perimeter’ and asking if it was always, sometimes or never true. Most of the children immediately said that it was always true. Then we went onto the challenge.

The children really enjoyed finding different shapes and working out different strategies to find longer perimeters. My visitor got totally involved with the lesson and proved his mathematically ability by working out that there was a maximum perimeter of 42 cm which I had totally failed to notice.

At the end of the lesson we had established why 42cm was the longest perimeter and the children were all a lot more secure in their understanding of both area and perimeter. The teacher was impressed by the children’s learning and their enthusiasm and so was I.


One thought on “Area challenge

  1. Chris Clarke (duckiec)

    Thanks for immaculate timing WW – was just planning this weeks Year 5 maths when I stopped to read your blog. I have used this investigation before (when I was a bright-eyed student!!!), but had forgotten all about it. Looks like the perfect double lesson to me.

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