Jig Shapes
Problem
This challenge is best done in a group of at least four children.
You'll need to print out this sheet or, if you would like much larger cards, these sheets. The sheets will need to be cut into twelve separate cards.
Share all the cards out amongst the group.
Can you each work out what shape or shapes you have part of on your card?
Can you describe the shapes without showing it to anyone else?
What will the rest of the shape or shapes look like do you think?
How could you sort the cards?
We would love to hear your descriptions and hear about the ways you sorted or arranged the cards.
This problem is also available in French, called Casse-tête de formes.
Getting Started
Can you think of a good way of arranging the cards?
Student Solutions
This problem encouraged you to work as a group to discover all of the different shapes on the cards. Part of the challenge was to describe the shapes (or part of them) on your own card and understand the explanation of others. In this way, you could work together to determine all of the different shapes in the Jig Shapes challenge.
Charlie, from The Haberdashers' Aske's Boys' School, suggested that it's good to try to describe the sides and edges that you see on your card. He also suggested describing any whole shapes.
We wonder whether any of you tried arranging the cards? Have a go - what happens?
We also received some photos of the finished problem. Thank you to both Ci Hui Minh Ngoc (who attends Kong Hwa School in Singapore) and Owen (who is home educated in the UK). Owen also recorded the different types of shapes in his solution. We wonder if you can name the shapes too and perhaps suggest some shapes that we might have included? Perhaps you might design your own puzzle for another group to solve, using some of those different shapes?
Here's is Owen's photo of his finished problem:
Teachers' Resources
Why do this problem?
The intention of this problem is that children will work together as a team. It should help in developing mathematical language about shape and position, as well as encouraging learners to listen carefully to others and tweak their own ideas accordingly.
You may like to read our Let's Get Flexible with Geometry article to find out more about developing learners' mathematical flexibility through geometry.
Possible approach
The cards have been designed to join together like a jigsaw so that the picures of the shapes are complete, but it may be better not to tell children this immediately. Instead, invite the group to find a way to organise or sort the cards. At this stage, members of the group can help each other find adjoining cards, but discourage them from simply giving someone else their card. If you are doing the problem as a class activity you could use sticky-tack to fix the cards to the board. Encourage the children to describe the shapes they can see as the whole 'jigsaw' is built up.
Alternatively, you could invite each group to hide two of the cards and challenge them to create the jigsaw without them. Can they draw what they think is on the missing cards? Is there more than one possible solution? Does the position of the missing cards in the jigsaw make a difference to how difficult it is to draw them?
Key questions
Possible extension
Learners who think this activity is trivial have not solved the problem! How can the cards be organised, arranged or ordered? Encourage them to help other members of the team in a cooperative spirit. They can also be challenged to make their own Jig-shape puzzle using all the geometric shapes they can.
Possible support
It may be appropriate for some children to share cards with someone who is more confident with language about shape than they are themselves.