Dear Amy,
Carissa is away for a time so I will try to answer your question. First of all you are on the right track to play games and build their skills before proceeding through the lessons. I would recommend you play "Corners" and let them continue their score keeping throughout the week. For instance, on Monday they play and get 65. Then on Tuesday they start with 65 and keep playing by adding more to it. That way they will see what happens to adding numbers beyond 100.

If they are not ready for that yet. Then start with Addition War{A44] and Short chain solitaire [A47]. If you find they are not successful with that perhaps they need to go back through some of the strategies. The addition strategies are listed in the appendix [p145]. I would not have them memorize the strategies, rather I would have them use their abacus and try to help them discover the strategies as you ask leading questions. For instance, if I put 7 on one line and 8 on another line, how can I quickly tell the answer without counting all the beads? You want them to discover that the two fives are the same color and then there are two beads & three beads making a total of 15=2 5s=10 2 3=15.

If this is not clear, it might help to call and speak to a customer service person directly as it is often easier in words than in this mode. 888-272-3291
Thanks.
Nancy