Olympic Flags
Why do this problem?
This problem is about arrangement and combinations. How many ways can the colours be arranged and can children find all the ways themselves?
Possible approach
You could start with the flags and look at the ones with vertical stripes, and then the ones with horizontal stripes. Show the children how to begin by choosing one colour to start with.
This sheet can be downloaded, copied and used or the flags could drawn on squared paper.
If possible, the children should work in pairs so that they are able to talk through their ideas with a partner.
At the end of the lesson everyone can show the flags they have coloured and discuss how many different ones have been found.
Key questions
What three colours have you chosen to use?
Which will you do first - the horizontal or the vertical stripes?
Which colour are you going to start with?
How many ways can you arrange the other colours?
How can you be sure you have found them all?
Possible extension
Learners could also design some flags which have three blocks of colour but which are different from the ones above. More adventurous children may like to try with four stripes - but beware, there are a lot of possibilities!
Possible support
Suggest using this sheet (enlarged if necessary) with two of each flag crossed out.