I got this book for my advanced 5 year old because he wanted the challenge of learning something new this summer, but I didn't want to push him into harder math that requires too much handwriting. This was honestly perfect! It was colorful and engaging, and so easy to understand. In fact, I sent the link over to our school's teacher as a possible resource for their whole class because it is so much easier to understand than their curriculum (as evidenced by my 5th grader still struggling with time). Within 3 days my son finished the first half and can tell time by hours. He usually gives up quickly and feels overwhelmed, but the use of white space and small chunks at a time were beyond perfect for him and he wanted to do extra. We'll work on the minutes next, and I think I'll have my 5th grader join us!