Back in the Seventies, one of the most popular games which took the UK by storm was Mastermind. It was aimed at 8yrs olds and upwards. It’s a form of code cracking where you have to work out the hidden line of coloured pegs. It was developed from a traditional games called Bulls and Cows which was originally played with numbers rather than colours. The term “bull” refers to the correct object being in the correct place in the line. A “cow” is correct object but in the wrong place in the line.
Like many strategy games, it can be easily adapted and played outside with gathered objects. Below is an example of how I did this:
First you need six piles of natural or found objects. I’m working on a bag, but a large cotton sheet would work better with a group of children or a class. How many you need of each object is a matter of debate – but probably 20 would be more than plenty. If you get to 20 lines without a solution, it may be time to show the children the hidden line up.
Next, put 4 objects in a row at the top of, and inside the bag. I choose a mussel shell, twig, bottle top and hazelnut.
Then I covered up my line of objects. It is important that the rest of the group do not see this line. It’s their job to work it out through strategy and logic.
The first person has a go. I’ve opened up the bag so you can see the difference. Only 2 of the objects are correct (2 cows) but they are in the wrong place (0 bulls).
The next person has a go. They have worked out that the stick and mussel are likely to be in the line up. In the 2nd row – see the photo below, there are 3 objects which are correctly in the line up (3 cows) but none are in the right column (0 bulls).
On the third attempt, a similar situation happens. 3 out of 4 objects are correct but all are in the wrong columns – 3 cows and 0 bulls.
With the 4th attempt, the person has got a lot closer to working out the line up. All the objects are correct and the red bottle top is in the correct place – That’s 1 bull and 3 cows.
The puzzle has been completed by the 5th row! The line-up the objects matches the hidden line up! Hooray! Normally it takes longer than this, but as I was just putting together a demonstration, I wanted something which would fit on my bag.
If I was introducing this game to a large class, there’s several ways of managing the groups:
- Firstly ensure that you have enough objects. The original Mastermind game allowed for 20 rows. It is also acceptable to have 2 or more of the same object in a row.
- Next, this can be demonstrated to the whole class. Split the class into groups of 4 and take turns for each group to suggest a line up, which will involve some discussion. A bit of scaffolding may be required to help children see the patterns emerging. Play a couple of rounds as a whole class.
- Set each group off to have a go – children can organise themselves to take turns. If one group gets stuck, then pair them up with a group where the children have got the hang of the game.
- Once groups are proficient, then this can be a useful finishing off game outside or in. The original Bulls and Cows game used a row of four numbers, not colours or objects! It is also possible to play the game using four letter words. These are all interesting next steps. Likewise, can the class work out the number of possibilities which exist when six natural objects are used to create lines of 4?
I hope this game has whetted your appetites for some mathematical investigations in the year ahead. Enjoy!