Sunday, 10 July 2011

Fractal Cuts

This week's resource of the week comes from Kangaroo Maths. It's a lovely practical activity which gives the pupils something to take home and show their parents, which I think is important.

It's Fractal Cuts! The very easy way of making a 3 dimensional "fractal" out of a sheet of A4 card (or paper). Google "fractal cuts" and you'll find it.

I used this activity with a class who are working at level 7, but I think it works for a huge range of abilities. I started off the lesson by showing them loads of pictures of fractals, and told them what they are in very simple terms: pictures where if you zoom in again and again, it still looks the same. Then I got them to draw a fractal (the Koch fractal, but of course I didn't call it that to them, that would be asking for trouble!) I used questioning to get the pupils to think about what is happening to the area and perimeter of the Koch as they draw more and more iterations. I think this touches on a very interesting concept: the area gets bigger and bigger each time, but doesn't go to infinity. I demonstrated this by drawing a circle around the shape, and the pupils recognised that the area will never be greater than the area of the circle.

Then it was the fun bit: making 3D fractals! I'd made one in advance, Blue Peter stylee, and the pupils were like: woah! I gave them all a piece of A4 card and a pair of scissors and took them through the process step by step. We managed to do more iterations than the document above suggests. We ended up with squares that were about 0.8cm^2. They looked so cool.

My plenary was getting the pupils to answer the following questions in their books: What is a fractal? What's special about a fractal's area and perimeter? Finish this sentence: I think fractals are cool because...

Why I love this activity:
-It's engaging and goes a long way towards ensuring all pupils are on task
-The pupils can take their fractals home and show their parents: good because it means parents then ask what it is and the pupil then talks about what they've learnt, which makes it more memorable.
-It introduces concepts of convergence and infinity in a very tangible way.
-It would make an impressive wall display (sadly I'm not allowed to stick anything up at all in my room because it might ruin the decor. I don't even have a noticeboard).

With the end of term approaching, why not try this activity as a fun lesson? It's better than showing a DVD :)

If you do use it, let me know how it goes!

Emma x x x

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