I have revised this freebie but the changes are largely cosmetic and I have included the Strategy Overview which may assist you. I start with the screener, then use the overview to identify the facts within a strategies framework. Teaching the strategy rather than the number fact in isolation works.
Start with adding Zero. This is usually easy and I haven't had a student who doesn't get zero at this level. As long as they can count you can start with the Count-Ons next.
I use lots of games to reinforce the strategies and if kids have used their fingers for years (and had little success) you will need to play lots of games to replace the finger-counting habit. While fingers can be accurate for adding 1, 2 or 3, there are better strategies for other facts. The revised list has some suggestions for games that may work for you.
I have many games at my store for you to consider and I am convinced that explicit teaching and games are the secrets to success.