Task 11

Materials and tools for a working group: 

Marble

The teacher bases his/her own table in front of the class so that it is slightly inclined but the slope is not visible at first sight. He will do it so that the pupils do not notice it. The activity can begin by taking a cube and a ball and placing it on a (pre-prepared – slightly inclined) table. The ball begins to move, teacher is giving it back where he wants it to be. He warns pupils that a strange thing is happening - the ball is moving itself, but the cube is not. It shows them more than once to see that the ball is so real. The teacher guides the pupils to think about what is causing it to happen: Think why, after laying on the table, the cube has remained in place and the ball has rolled out of the table down? Are the balls rolling themselves apart wherever we lay them?

He then leads the pupils to look for three places in the classroom where the ball is rolling and the three places where it will lie where they put it. It leads pupils to compare the qualities of these places and guides them to create explanations: What do we need to do with the tables to keep the ball on it exactly where we put it? Pupils‘ own explanations can be formulated very differently, it is important to emphasize the essence they express.