Standardized Test Tutor: Math: Grade 4: Practice Tests With Problem-by-Problem Strategies and Tips That Help Students Build Test-Taking Skills and Boost Their Scores

It was challenging for my 4th grader, but good.

The three tests in the book do an excellent job covering all the material for Grade 4 math. I haven't seen a book do this before, but the answer key in the back goes so far as to explain why EACH of the multiple choice options (A,B,C,D) are right or wrong. It's a very thorough book.