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'Chain of Changes' printed from http://nrich.maths.org/
Why do this problem?
will help children to refer to the shapes by name and visualise the next shape to place in the pattern. They will need to look carefully at the properties of each shape. It will also encourage them to use a trial and improvement approach in solving problems.
You will need plenty of Logic Blocks or of shapes cut out from this sheet
which has two copies of each of the shapes. A full set of Logic Blocks can provide enough for four children, pairs or small groups depending on how the children are working. (One group has the large, thick pieces, one the large, thin pieces and so on).
You could start with one of the pieces and ask children to describe it. Ask if they can find one which is the same shape but a different colour. Then you could go on either using the large, thick blocks or this interactivity
to make sure that all in the group really understand the problems to be solved. After this the children could work in pairs
or threes on the actual problem so that they are able to talk through their ideas with the others.
At the end you could discuss the different ways that the children found of doing the first part of the problem. Then discuss why there was not a way of doing the second part using all the pieces. Children could also discuss the pattern that results in changing shape and colour alternately.
The work makes a good display using either the children's own drawings or paper copies of the pieces using this sheet
Are you going to change the colour or the shape this time?
Which shape are you going to use next?
Can you find another way of doing it?
Why can't you use all the shapes this time?
Those who find these tasks straightforward could use a full set of Logic Blocks and also change the size and thickness of the pieces.
It might help some children to make their own chains which started with the blue triangle, but without specifying the end point.