Investigations

Materials:

  • ten of the same circular objects (e.g., counters, coins, trace a coin ten times and cut out the circles) or use this interactive tool.

10 circles arranged in a triangular shape 1 circle in the top row, 2 in the next row, 3 in the next row and 4 in the bottom row. An arrow pointing to a triangle outline with the top point of the triangle pointed down.

I have made a triangle shape by arranging these circles.

Can you move some of the circles to flip the triangle so it is pointing down?

How many moves did it take?
Can you do it in 5 moves? 4 moves? How about 3 moves?