On Thursday last week, Zachary wanted to know how many years he and I had between us. To motivate him to learn addition, I had him first calculate our combined age by counting my age in cheerios, his age in cheerios, then combining the two sets of cheerios and counting them. That takes a long time. Then I showed him how to do addition with two digits in at least one of the addends. Here is a picture. Also, on Saturday, I introduced both Zachary and Chayce to the positive real integer number line, which they both found quite intuitive to use for single digit addition.
