There are many ways to teach numbers to kids. Abacus is a great tool to teach your child simple math such as counting, addition, subtraction, multiplication, and even division. This is the “A” book of Level-4, which contains Plus and Minus of triple-digit numbers mentally, multiplication of triple-digit numbers with the single-digit numbers. It also contains the division of Double and triple-digit numbers with the single-digit number. It helps in the whole brain development of a child. These books are very attractive and are of very good quality.