This was a fun and practical lesson I did recently looking at money. Firstly, in pairs children tried to find the 4 different combinations to make 5p, which are:
I put this up on the board and I kept challenging the children to see if they could find another unique way of doing it (“a million pounds to the first person who can come up with a new way!”). This gave me the chance to show that just re-arranging coins in order doesn’t make a new combination, for example:
2p+2p+1p is the same combination as 1p+2p+2p.
The children then went away in pairs and, on a big piece of A3 paper, they had to try and find as many different ways of making 10p as possible.
I let them know that there are 11 possible ways in total, which helped them know when they had them all and gave them a target to aim for. As further motivation, I said that I’d written down one combination and if they managed to get this combination somewhere on their paper then they’d get a cheer from the class and a point.
When children had finished and believed they had EVERY different combination, I gave them a final sheet (pictured above) to fill in to check. This was great for them to see if they actually had unique combinations or if they’d done duplicates by mistake! Children that hadn’t quite finished were also given this sheet about five minutes before the end of the lesson for support. The final sheet was a good discussion point for a plenary, showing how you can work systematically by starting with a certain combination and then breaking it further and further down.
Children that managed to find every combination and who filled in the final sheet before our time was up were given a quick challenge question to do on a whiteboard, such as:
‘How many ways only used copper coins?’
‘How many ways used a silver coin?’
‘If you had no 2p coins, how many ways would you be able to make 10p?’
‘How many ways do you think there are to make 15p? How many can you find?’