I ended up really only using some workbooks that came with 4/5 with my 4yo and 5yo. We did read the books that came with 4/5 but now on the recommended schedule and we basically read through them by November. We read aloud chapter books now and sometimes go back to the 4/5 books just for rereads. My 5yo is doing the K Language Arts (beginner reading level). That has been right on for her! My 4yo likes to do the Explode the Code workbooks as well so I ordered more for her. It didn't take long for my 5 yo to read the short tales! I'd say by November she had it down---I've actually skipped a bit ahead to keep her interest level because she picked up letter sounds pretty fast. The program is fun! I should add that my 10yo is using Language Arts Grade 5 and we both love it. It's very thorough and the book titles are outstanding! I highly recommend it!