Subtraction
The fastest method for subtracting a smaller number from a larger number with an abacus is to learn to either directly subtract a number digit directly or by grouping the number digits by 5 or 10. We call these grouping methods, the Five (5) Extras or Ten (10) Extras for Subtraction. The links for the lessons to add and subtract directly are in the Getting Started section. Use the Subtraction by Grouping link to study the lessons for subtracting using grouping with whole numbers and decimals.
Subtract 3 in column 1 by counting
Subtraction by Counting
The simplest way to add subtract numbers with an abacus is to set the first number. Then pull one bead at a time to the bar, counting each bead until you have reach the digit you are subtracting. When you have "counted" each digit, you have successfully subtracted the number. In the link, Subtraction by Counting, we guide you through the special situations you may run into in subtracting two or more whole numbers and decimal numbers.