Concepts in Action: Sensorial demonstration of the difference between H1 and H2

Age
6-9.

Materials

 * Triangle fraction insets: whole, 3/3
 * Constructive triangles: H1, H2 and two red T3

Presentation

 * 1) Verify the congruency between the triangle whole inset and the small red equilateral triangle, by superimposing the inset on the wooden triangle.
 * 2) In the same way, we can see that this metal inset is equal to 1/6 of the grey trapezoid.
 * 3) Superimpose H2 on H1 so that the vertices of the grey hexagon coincide with the midpoints of the sides of the yellow hexagon.
 * 4) Place the 1/3 metal inset pieces over the yellow portion that remains visible.
 * 5) With this material we can cover only three places.
 * 6) However these three obtuse-angled triangles equal one small red equilateral triangle.
 * 7) Move the three thirds to the three remaining vacant spots; these three triangles correspond to the second small red equilateral triangle.