Constance Kamii , noted math educator, writes that children “invent” arithmetic. As seen in the documentary film Empress of Everything: Messages from a Master Teacher, every day youngsters invented arithmetic at The Classroom at Carpenter Lane (1988-2005).
………………………………………………………………………………………..
Here is a closer look at the CCL Abacus (pat.pend.)
Here is the game board for Tens, as seen in Getting a Feel for Numbers:
Here are the rules for the game TENS
Shuffle a deck of cards.
Set the cards face down on the board in the place that says deck.
Deal four cards from left to right into the spaces at the top of the board.
Look for cards that add up to ten. Good news: all face cards count as ten. An ace counts as one.
Pick up any cards that make a ten, and put them face up in the place that says tens.
Deal again from left to right. You will sometimes be putting a card on top of another card when you deal. That is exactly how you play the game.
Look carefully. Sometimes when you pick up the cards that make a ten, you will expose a card that will help you make another ten. Pick up that ten and put it in the tens place.
The game ends when you have dealt all the cards and made all the tens you can.
Scoring: Pick up the top cards that make a ten. Put them down in the empty space between the tens place and the deck place. Keep on counting the tens by ten (10, 20, 30. .) to get your score.