The basics of addition and subtraction are presented in two-page explanations and demonstrations. Each book contains a detailed table of contents, a one-page index, and a table of subtraction and addition terms. Problems and examples are explained and profusely illustrated with pen-and-ink drawings. Unfortunately, there are no practice problems. These books would serve as quick references or beginning guides for teaching math, but it's unlikely that children will pick them up. They might be a reasonable purchase for libraries that have a home-school population.