Why Must Read Primer Level - Performance Book: Piano Adventures?

I am using all three books: lesson. theory, and performance. I am not a professional piano teacher, but I do know enough to teach my 11 year old son. I was first using flash cards and performance songs that my youngest son used when he was learning piano. My grandson soon grew bored of these. Then one day, I showed my grandson the new books and he immediately liked them. He went through 20 pages the first sitting. Then we went to the theory book and next the performance book. We are not finished yet, but my grandson told me he likes to work in these books. I highly recommend these 3 books as teaching aids for teachers of younger students.