Pick 10...

Pick 10 rods. Arrange them however you like. Draw them. Write what you notice.


Proposal to children: put the rods in trays. Keep them by sliding them onto the floor.


"In the course of this free play, the child learns many things about the rods upon which, later on, he will be building his mathematical knowledge. He will discover:
 1. that rods of the same colour are equal in length;
 2. that those of the same length have the same colour;
 3. that those with different colours have different lengths;
 4. that if he wishes to make equal lengths he can only do so by putting particular rods end to end;
 5. that the rods have been made so that whatever he constructs corresponds to the number of white rods."

Caleb Gattegno, Now Johnny Can do Arithmetic [1963]

Rods being used during general free play

Some children raided the rods boxes during their play activities in the classroom. I think it's some sort of ship.

Making 100s

Back in April or May, two children in the class were playing with the 100 tray. They like it because it's the biggest. They started to put the hundreds they were making on the carpet and make more, so I put down some masking tape to give them a border to work to. More children joined and got obsessed, eventually they made this:

We counted what we had afterwards. And then discussed our counting:

  • When we were counting, each had their own pattern and some of them were the same.
  • 100 white piece fit in a tray.
  • When we counted 100, 200, 300, 400, 500, 600, 700, 800, 900 ____ . Some people were saying ten-hundred because it’s kind of confusing.
  • Also we were saying 10, 20, 30, 40, 50, 60, 70, 80, 90, twenty! Because the 90 sounds like 19.
  • If we put rods in the orange boxes, then not all of the colours we put made 100.
  • That we had to be careful and not break the things we made.
  • We got to 10,000!