When N was younger, i used the flashcard method to introduce to him shapes with 5 sides and more (heptagon, nonagon, dodecagon, pentagon etc).
I recently tried to 'test' him to see if he remembers, he seems to be able to differentiate the shapes...but im not sure. Anyway, i brought these cards out again, because this time i want him to learn which shape has how many number of sides/angles.
I got this idea from another blogger mom (I CANT REMEMBER WHO?!!). Using ice cream sticks, i got N to place each stick on each side and count the number of side that shape has. By doing this, he now knows that a Heptagon has 7 sides.
And a dodecagon has 12 sides. I should say N AND Mummy learnt together. I never knew what these shapes are called untill now!