Why do this
problem?
This activity will encourge children to talk together about
their thoughts and ideas. It will help them gain familiarity with
the properties of shapes and relevant vocabulary.
Possible approach
Learners will get the most out of this activity if they have
real shapes to handle. The problem is based on Dienes' Logiblocs
but if you don't have these, you could just use the pictures in the
problem. You may also find
this sheet
useful which contains cards to be cut out. Each card describes a
particular shape.
Before having a go at this activity, pupils are likely to need
some time simply to 'play' with the shapes so that they are
acquainted with them before being asked questions about their
properties. You could then choose two shapes from the set and
invite learners to say what is the same and what is different about
them, as at the start of the problem. You could also print off
the cards and
invite a youngster to pick a card, read it and find the appropriate
shape which matches the description. These initial tasks will help
to familiarise children with the necessary language so that they
can describe the whole set of shapes.
In order to introduce the idea of a difference map, you could
use a large sheet of paper, or a mini-whiteboard and physically put
a shape on it. You could then talk through what you are doing as
you create a difference map with three shapes in total, laying the
shapes on the paper and drawing in the lines. You might like to ask
some children to do a similar thing for the whole group.
Set them off on the challenges in pairs using the shapes or
the description cards. This is an ideal opportunity for
you to listen to their conversations and to assess their grasp of
the vocabulary and the way they are going about the task.
Key questions
Tell me about this shape you have chosen.
Can you tell me anything more about it?
What do you think about [another member of the group]'s
suggestions about his/her shape?
Which shape could go next to this one on the difference
map?
What are the differences between these two shapes?
Possible extension
Many children will enjoy creating their own blank map for
another child to complete. Of course the map doesn't have to be a
closed loop - it could be a line, for example. Some learners could
investigate the number of different ways they could fill in a
particular map with different shapes.
Possible support
The
Chain of Changes problem would be a good one for learners to
try before tackling this problem. When
creating difference maps, some pupils could start by
keeping one or two shapes the same as those on your
map.