My children love these workbooks. They beg to do these workbooks. The pages are very engaging and colorful. The games, riddles, jokes, and puzzles make math a lot of fun. In the first third of the book there are brief explinations on how to do the problems (a little teaching/explaining, but not much). Plus, they are a good size workbook for a good price. We bought our first set at Costco to get ahead for the next year (awesome summer practice!) and have since used them for homeschooling while moving (bought on Amazon). Highly, highly recommend!
As a former high school math teacher, I spend lots of time trying to teach my boy math and I have found this book to be right up our alley. Most pages have only 5 or 6 problems and I think that's about all a kid needs to get their brain going. The problems increase in difficulty from page to page so when it is all said and done I feel like he's really done a lot of thinking. What I really like about this book is that it is 3 books in one. There are basic skills (colorfully presented in a variety of ways), then games and finally real world problems. This allows your child to study every concept a bit and then review them all again in games portion and then apply them in the 3rd "book" within this 1 book.
My son is a reluctant student but he hasn't put up much of a fight with this book because it isn't overly laborious and provides colorful variety. Having full color pictures of money, cupcakes, etc... has really made it all seem like stuff he should know so there is very little, if any, arguing about why we have to do math in the summer. We also give him a sticker for each sheet he completes and then as he meets milestones he gets rewards. This book was great for us. I also find that we can breeze through a pages during a meal. I'll show him the pages, he does all the thinking and I write in the answers so he can eat before supper gets cold. Pretty painless for everyone and he's so prepared for 2nd grade that they'll hopefully skip that and let him stick with 3rd or 4th grade content.