In short, these are the resource books to use when your students need practice on one specific topic. Unlike most textbooks and many resource books, these two books don't go off in a thousand directions and throw in a lot of poorly written word problems.
While the books claim to be for late elementary and middle school grades, I've used them exclusively with high school students as they are sufficiently challenging and cover all the necessary topics.
If you want a chance to win both, send an email to teachforever@gmail.com with the subject "Skill Builders" by Tuesday 7/3, 11:59pm CST. Good luck!