I’ve been trying to play some more teaching games with Anya. Today’s activity was building our own guitar-like instrument. A small box with a hole cut in it would work well, but we used a couple of her board books. Stretch a few rubber bands around the book (I’m a little uptight, so I put them in a specific tonal order … hers are a haphazard arrangement), then insert something under the bands along the book to raise the bands up a little bit from the book. A wooden block, a marker, and a glowstick all worked well. If you put the object toward the center of the rubber bands, then you get two different notes per band.
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.