Great books! We do these books every year over summer break so my kids don't forget what they've learned that year and we've never had any complaints. I recommend them for all ages.
My daughter needed a workbook over the summer to help her prepare for 5th class and this was great. She diligently worked on this daily and really was able to hit the ground running when school started. It had a good variety of subjects and she even seemed to enjoy her summer "homework"