How to Use an Abacus With Nine Beads

Slide beads from left to right when using a nine-bead abacus. The first row represents ones (1-9); the second tens (10-90); the third hundreds (100-900), etc. To represent the number 6, slide 6 beads on the top row fully to the right. To show 16, slide 6 beads from the first row to the left, and one bead from the second row (this "reads" 10+6=16). Moving left to right, beginning with the top row and moving down through the place rows, you are now prepared to represent numbers like 732,981.

Add numbers using the same left-right motion. To add 3 to 6, slide 6 beads to the right in the ones row, then slide 3 more; count up your answer. To add 3 to 8, you will need to perform two operations. Slide 8 beads to the right. You need 3 more beads, but the ones row only shows one bead remaining. To finish the sum, count your ninth bead as 1, and slide it to the right. For 2, slide the nine beads in the ones row back to the left and move one bead from the tens row to the right. For 3, move a single bead from the ones row to the right. 3+8 is represented by 1+10 on the abacus. Your answer will always "read" as a translation of the sum into how you can add it in 10s.

Teach simple subtraction using the same left-to-right motions. 9-3 involves moving all the beads in the ones row to the right, then moving 3 beads to the left to produce the answer of 6. While simple sums may not be exciting to you, working with a nine-bead abacus is a great way to clarify many math concepts that may confuse children: the reciprocity between adding and subtracting, the relationship among the words "minus," "subtract," and "take away."

Employ a nine-bead abacus in less conventional ways to teach concepts of multiplication and division.
Using vertical rows, irrespective of place values, move two beads to the right in each row to illustrate 6 x 2 = 12. Beads can also be grouped to illustrate division. A child who finds it difficult to memorize multiplication tables quickly can be helped by using the abacus to work out problems hands-on. Again, you can teach the reciprocal relationship between multiplying and dividing.

Encourage your child to develop abacus games of his or her own. Games can involve concepts like "more" and "less," "big," "bigger" and "biggest." Select rows to keep track of the number of pairs each player makes in a matching card game. As your child becomes familiar with math concepts, he or she will develop ideas about how to use this learning tool.