First of all anytime I am going to have the kiddos use dry erase boards - it's important to allow them time to just draw or write. This gives them the freedom to do what they want to do and be able to focus when I need them to.
I decide on a secret word and write it on my dry erase board, but I don't show the kids. Then I call out a letter of the alphabet. The kids look on the word wall and write one of the word wall words that begin with that letter.
Then, I reveal my secret word. If they wrote the same word I have - they give themselves a tally mark. If not, they don't get a tally mark. SO simple, yet a great word wall activity and the kids LOVE LOVE LOVE this!!