This is a set of 4 books ranging from 2 digits to 2 digits x 2 digits and 3 digits for the popular young learner. The book type of teaching book shows answers at the end of each roll. This kind teaching material is easy to understand using diagrams. (Each roll has a B5 format and 48 pages) Chibiko Abacus 4 ● 10 grade Kiso (2 digit est) ● Chibiko Abacus 5 ● 9 class Kiso (introduction of 2 digit x 1 digit multiplication and 1 digit subtraction of 2 digit markers). Chibiko Abacus 7 grades of 7 (2 digits x 2 digits multiplication / 3 digits by 1 digit business division) *Multiplication is the division of division... When this set is complete, the next step is the Chibiko Abacus 8 ● 6 class Kiso