I came up with a game to visualize the concepts of addition and subtraction. I asked Anya to get a couple of stuffed toys and line them up on the floor. She brought three. I then asked her to hide one under the table and tell me how many there were (2). Then hide two under the table and see how many (0). Then take one out from the table and put it in the pile – now we have one. Add two more – we have three. Add one more … oops, had to run upstairs and get another one. Now we’ve got four. Subtract two – hide them under the table. Now that the terms ‘add’ and ‘subtract’ have been introduced, I began to just say ‘add #’ and ‘subtract #’.
Then we worked on a little algebra — you have two in your pile now. How many do you need to add to make five? Don’t know … well make a second pile … three, four, five. How many are in that second pile? Three – so if you have two and want to have five … you need three more.