Books

Abacus Addition: This is the introductory text for learning to add using a single abacus. The first three chapters explain the fundamentals of the abacus and the basic methods for adding and subtracting whole numbers. These chapters are followed by several chapters on learning to add whole numbers using grouping by 5 and 10 (called 5 extras and 10 extras).  The final chapter explains adding decimals and columns of decimal numbers.  The document, A Short History of Numbers and the Abacus is also included in the appendix. 

Abacus Addition by Counting: This is the introductory text for learning to add using the abacus by counting. The first three chapters explain the fundamentals of the abacus and the basic methods for adding and subtracting whole numbers. These chapters are followed by several chapters on learning to add whole numbers using 4 rules for adding by counting on an abacus. The final chapter explains adding decimals and columns of decimal numbers.  The document, A Short History of Numbers and the Abacus is also included in the appendix. 

Abacus Subtraction: This is the second introductory text for learning to subtract using the abacus. The first two chapters explain the basic methods for adding and subtracting whole numbers. These chapters are followed by several chapters on learning to subtract whole numbers using grouping by 5 and 10 (called 5 extras and 10 extras).  The final chapter explains  subtracting decimals and columns of decimal numbers. 

Abacus Subtraction by Counting : This is the second introductory text for learning to subtract using the abacus by counting. The first two chapters explain the basic methods for adding and subtracting whole numbers. These chapters are followed by several chapters on learning to subtract whole numbers using 4 rules for subtracting by counting on an abacus.  The final chapter explains  subtracting decimals and columns of decimal numbers. 

Abacus Multiplication:   In this text we turn our attention to Multiplication calculations. We start with the most basic method of multiplication in Chapter 1.  Then, in the remaining chapters we progress from multiplying with single digit multipliers (the second number in your multiplication calculation) in Chapter 2, to single digit multiplicands (the first number in your multiplication calculation) in Chapter 3, to multiplying any size numbers in Chapter 4. Lastly we learn how to multiply decimals in Chapter 5 (which is really very simple). 

Abacus Division: This is the text for learning to divide using a single abacus. Chapter 1 covers Basic division, the terms used in division calculation and how to divide the division facts. Then we move to dividing with single digits, called Short Division, in Chapter 2. This is followed by learning division calculations with larger numbers, called Long Division, in Chapter 3 and Long Division with Larger Divisors, in Chapter 4.  The final chapter of this text, Chapter 5, focuses on dividing decimals (there is a really simple technique for doing this, too). 

Simplified Abacus Division: In this text, Chapter 1 covers basic division, the terms used in division calculations and how to divide division facts with the Double-A method. Then we move to dividing with single digits, called Short Division, in Chapter 2. This is followed by learning division calculations with 2-digit divisor and larger numbers, called Long Division, in Chapter 3. In Chapter 3, we will introduce the division techniques of the “higher divisor”, the “lower quotient”, and upward adjustment. Using these techniques, we will perform division calculations with 3 and 4 divisors in Chapter 4. The final chapter, Chapter 6, focuses on dividing decimals using the same techniques from Chapters 3 and 4 and a very simple additional step   

Abacus Fractions: In this text, you will learn how to calculate fractions, with a single abacus,  in 3 chapters. Chapter 1 covers Basic Fractions, reviewing how to reduce fractions and find the lowest common denominator. Next, Chapter 2 shows the student how to add and subtract fractions.  Lastly, Chapter 3 covers multiplying and dividing fractions.  

Simplified Abacus Fractions: This text is similar to the Abacus Fractions text. It also has 3 units: Basic Fraction, Adding and Subtraction Fractions, and Multiplying and Dividing Fractions. The Basic Fraction unit reviews how to reduce fractions and find the lowest common denominator.  Since adding and subtraction use a common denominator, these tasks are grouped into Unit 2 in their separate chapters.  The steps to multiply and divide fractions are very similar so they are grouped together in Unit 3.  The Double-A method (2 abaci) is used in this book  which (as you will see) will simplify all of your calculations with fractions .