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'Robot Monsters' printed from http://nrich.maths.org/
Why do this problem?
involves measurement that really focuses on number work - addition, ordering numbers and combinations. Manipulating the pictures can also help pupils to explore the different combinations systematically.
You could start by showing the whole group the pictures in the problem on a computer. Young children will probably want to discuss these. Explain that each Robot Monster needs a head, a body and a pair of legs. You could ask how tall a picture of a robot would be using a certain combination of head, body and legs.
Then you could set the task in the problem. If the children can have pictures from this sheet (doc
) they will find the activity more enriching. The
doc version has the exact measures, while the pdf does not. [If these pictures are printed onto card and laminated they will make a lasting resource.] It is helpful if the children can work in pairs so that they are able to talk through their ideas with a partner.
At the end of the lesson the group could discuss the tallest and shortest robots, and all the different combinations they have found. If you have made pieces printed onto card, these could be fixed onto the board so that this discussion can be illustrated.
If a Robot Monster is going to be as tall/short as possible, which head will you choose?
If a Robot Monster is going to be as tall/short as possible, which body and set of legs will you choose?
Can you think of a good way to find all the different heights you can make?
Why not start with one head and look at all the different ways you could add body and legs to it?
How are you going to record what you have found out?
Learners could make their own robot monsters in different sizes or try Find the Difference
or The Tall Tower
Suggest using the pieces from this sheet and trying it out practically.
Handouts for teachers are available here (pdf document
), with the problem on one side and the notes on the other.