This is one of a series of problems designed to develop learners' team working skills. Other tasks in the series can be found by going to thisarticle.
What are you aiming to do?
For the task:
The team has to find the rule on the Ruler's card, using the minimum number of tests. A test is asking whether a particular domino obeys the rule.
As a team:
finding out what others think
giving reasons for ideas
reflecting on what has been said
allowing everyone to contribute.
The team can be made up of four or five people of which one person is chosen to be the "Ruler". If you do the task several times, members of the team can take turns at being the Ruler. You may also wish to appoint an observer.