I was at the New York Annual Math Teachers Conference in Buffalo (http://www.amtnys.org/) a few years back and one of the teachers was telling me about working on strategies to make ten with his students. I had read about the importance of giving students who don’t naturally develop their own strategies for this in “Elementary School Mathematics: Teaching Developmentally” by John A. Van De Walle. I left the conference with some inspiration to come up with an activity to help reinforce making ten strategies.
While I’m not a big Tetris player I thought there was something in sets of falling blocks that could relate to making ten problem solving. I eliminated the odd shapes in Tetris and made horizontal shapes fall every time the player requested one. Like Tetris the goal is to not let the pieces stack all the way to the top. In order to prevent this the player needs to combine the sets of blocks into horizontal rows of ten to remove the blocks and and earn points. Thus using making ten strategies to play the game.
It all seemed to come together pretty well.