The target group of my exercise was a group of nine-graders who were about fifteen years old. During my teacher training in Uotilanrinne comprehensive school I carried out the following exercise with my students.

My aim was to deepen the pupils’ awareness of different materials and their features. The knowledge of different materials and how they behave helps the pupils to work with them and to use them as building materials.

The materials we dealt with were metal, wood and plastic. All the materials used in this exercise were to be found in the classroom where the working normally takes place. In this exercise the object could be e.g. a piece of metal, wood or a tool or anything else the pupils could find in the classroom.

To begin with, I divided the pupils into three groups (about five pupils in each group). Each group had all three materials to deal with and the task was to collect as many objects of each material as possible in five minutes. After they had their objects in one place I gave them a new task. The new task was to arrange their objects by categories which were:

1. weak

2. strong

3. easy to form (mould)

4. sharp

5. conductive

They had ten minutes to do this task.

The subtask was to answer the question “Why is this object made particularly of this material?”

The first task was clearly easier for the pupils than the second one. Pupils gathered all kinds of objects on tables and were very busy. After I had told them how to proceed after the first task the pupils were a bit confused. I had to explain them quite a few times how they should carry out the subtask. Finally they managed to group their objects and we began a discussion on how each group had arranged their objects.

The results varied a little but generally the task was understood quite well. They for example realised that a saw is made of metal because it is stronger than wood or plastic and the handle of the saw is made of wood or plastic because it is easier to form than metal and it feels better in your hand than metal. We also managed to go a little deeper in the material knowledgement when we discussed for example the blade of a hacksaw.

The idea of this exercise was to get the pupils to understand different features of different materials and how each feature effects its use when we are building or making something. It is clear that we use a hammer to hit nails into wood or that we heat plastic to form it or why electric wires are covered with plastic etc. It is not always clear why we use a certain tool or method to do so. This is what I was trying to teach the pupils.