There are three books in the Scratch Your Brain Where It Itches series; Book A-1 is targeted at students in grades 1-3, Book B-1 for grades 3-6, and C-1 for grades 7-9. The books are subtitled "Math Games, Tricks, and Quick Activities," which accurately summarizes the content of these math supplements.
Book A-1 covers place value, addition, subtraction, multiplication, and shapes. Unlike the next two books in the series, many of the activities require either a partner or a group, limiting its usefulness for home-educating families.
Book B-1 covers place value, operations, shapes, measurement, money, time, the calendar, and using calculators. These are primarily "brain teasers" done with paper and pencil, mental math, calculators, and manipulatives.
Book C-1 covers mathematical thinking working with number concepts, logic, visual puzzles, and arithmetic skills at a junior high level.
All books are available only as ebooks, and answer keys are at the end of each book.