CAFE CHALLENGE: heads up

You know when you need to stop, rest and grab a quick coffee – but you also know you need to keep the children focused on something more meaningful than a mobile phone game.

Well, here’s a good way to give your children chance to think mathematically, we call it: Heads Up

This one focuses on getting the children to think through multiple possibilities and to reason out which would be the most effective. This is problem-solving and mathematical reasoning.

 

Heads and/or Tails

This problem is based on a very short, but puzzling story. You don’t need anything, but having a collection of spare change on hand will mean the children can test out their ideas with real coins.

 

Here’s the challenge for your children:

James has a number of 10p coins. He lays them out on the table and then notices that exactly half of them are heads up.

A moment later his mum turns over two of the coins and now a third of them are heads up…

How many coins did James put on the table?

 

 

 

 

 

ANSWER

James started with 12 coins. 6 were heads up.

When his mum turned over 2 of the ‘head’ coins there were only 4 heads up.

4 out of the 12 is a third.

If you children work this one out fairly quickly ask them to create a new puzzle using the same idea of coins and fractions. If you wish you can post their puzzle in the comments below… we’ll even hunt out a prize for you!

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