We hit our first snag last night. Robbie stumbled a bit reading "Dog Bug" after his lesson. I think he was just tired, but I decided to back up a bit and slow down to make sure he's ready to move on.
Today, he re-read "Pop Fox", "Fun in the Sun" and "Dog Bug". He did extremely well on the first two and read the third pretty well. I've decided to do the Unit 4 review with him tomorrow and let him re-read some more books along with "Dog Bug". If I'm satisfied with his fluency, we'll move on into Unit 5.
Unit 6 has an intro to compound words, so I want to make sure that he's mastered the one-syllable words before we hit that.