Guess which one is bigger

Introduction

By experiencing this challenge the children will express their intuitive knowledge on areas and will check their hypotheses.

Preparation

Pick from the Tetrakys materials two rectangle and two scalene triangles.

Procedure

  1. The facilitator shows the children two triangles of equal area, one equilateral and one scalene.
  2. The facilitator then asks the children: which one is bigger?
  3. If the children answer that any of them is bigger, you should say: This one is longer, or broader, but which is bigger? Touch them with your hands.
  4. The facilitator lets the children verify it. We must wait all the necessary time for the child to discover how to verify it.
  5. The children will be able to determine from previous games that both two rectangle and two scalene triangles can be form two equal parallelograms. Each of the triangles is the half of the equal parallelograms, so both triangles have the same size.
  6. If the children are in school age they should be asked to express their conclusion with words, but allow them to do it in an infantile language. In pre-school children it is most important that they have the intuitive knowledge though they do not express it.