This activity was created by a five year old as he was playing with plastic teddy bear counters. Many opportunities arise in the classroom to have children explore Lachlan's task; after a story or poem relating to bears or as an extension to another mathematical activity when children are using counters.

The initial part of the activity, when the arrangement of bears is set up, involves counting, sorting and pattern. The problem itself requires the children to decide upon a logical strategy to move the teddy bears so that no two adjacent bears are the same colour. As the children work together they have to engage in mathematical conversation as they explain their plans and negotiate which strategy requires the least number of moves.

Some children may need to begin with two bears of each colour in order to decide how to proceed with the larger group of four. Others can extend the activity by using sets of five or more bears. To extend their thinking and use their prior experience, before carrying out the follow up activity children should be encouraged to predict how many moves it will take to rearrange sets of five or more bears and to explain what evidence they are basing their prediction on.