I loved what happened in math class this morning - so one more post (with pictures this time) about our new theme of Growing Patterns/Algebraic Thinking. This lesson is called Tables and Chairs.
Today I posed this problem. I told the children that restaurants often have different sized tables to accommodate different sized groups of people - but the restaurant I was thinking of only had small square tables. I drew a square on the board and drew a dot on each side to represent chairs. I asked what would happen if a group larger than four came to eat? Immediately, the children knew that restaurants "squish the tables together". So, the question - If two square tables were squished together how many chairs could you have? "Eight!" came one response. "No, Seven!" came another. I drew the squares "squished together" and put the dots around. It turned out that only six chairs fit.
Like yesterday, we continued discussing and drawing on the board as more and more tables were added. I drew a chart to collect our data, and we noticed a pattern in the chairs column - each time a table was added, 2 more chairs could be added. After we got to 5 tables, I asked, "Okay, now we have five tables and twelve chairs. Think! How many chairs will there be when there are TEN tables?" Several children were confident with their answer - "24!"
Partners worked this out together. Each partnership used squares and beans to build the models, then they drew each model on a piece of paper. Finally, they entered the data on a chart and found - ta da! - that the actual answer is 22.