# What Abacus Should You Buy?

To get started with the RightLobeMath.com online math program, we need an abacus or preferably a Japanese Soroban which can be purchased at anytime on Rightlobemath.com. We highly recommend in the beginning of a student’s abacus training that they use a “physical” abacus and not a “digital” abacus. The reason for suggesting the use of a physical abacus is the user’s sense of touch will be much stronger on a physical abacus than using a digital one like on a tablet or smartphone. The sense of touch or feel is important to help speed the student’s mental visualization of the abacus. This visualization technique will be instrumental in all mental calculations. Although we are strongly recommending the use of a physical abacus by no means are we saying don’t use digital versions. There are many PC, tablet, and smartphone abacus applications available, many for free. We recognize the convenience of using a digital abacus. Therefore we expect most of our students will utilize both physical and digital versions of the abacus.

Before we obtain our first abacus we must know what type of abacus to purchase. We recommend and throughout the RightLobeMath.com online math program we will only use the Japanese version of the abacus called a Soroban or counting tray. It is possible to use other forms of the abacus such as the Chinese Suanpan by using only 1 bead on top and 4 beads on the bottom.

The difference between the types of abaci are the number the beads per rod. The Japanese Soroban has 5 beads per rod while the Chinese Suanpan has 7 beads per rod. The reason for the difference in the number of beads is the Soroban uses a “base 10” numbering system while the Suanpan uses a “base 16” numbering system. We will discuss base systems in more detail in another post. Since the Japanese Soroban is simpler and uses our standard base 10 numbering system we highly recommend using the Japanese Soroban as your working abacus.

The most important feature to notice about the Japanese Soroban is the number of beads on each vertical rod, 5 beads. You will notice there is 1 bead at the top separated from the 4 lower beads at the bottom by a horizontal bar called the reckoning bar. Again we recommend you purchase the Japanese configuration of the abacus.

The Soroban is ideal for teaching mathematics because the Soroban is built on the same base10 number system, i.e. numbers 0 through 9, we use everyday. Sorobans come in varying sizes with different numbers of vertical rods where each rod represents a digit, 0 through 9, of a base10 number. So the more rods on a Soroban the larger the numbers it can handle. Typical starting Sorobans will have 13, 15, or 17 rods. Any Soroban of this size will be more than adequate for a beginning Soroban student. A 17 rod Soroban can count up to 100 quadrillion!

You will find professional Sorobans with 21, 23, 27 or even 31 rods but these larger Sorobans can be purchased later on when the student is working with very large numbers. For a beginning student a 15 or 17 rod Soroban is an ideal choice between size and ease of use. We recommend purchasing an inexpensive starter plastic Soroban which can be purchased at Rightlobemath.com or several other online retailers such as Amazon or Ebay. Much more expensive handmade wooden Sorobans will cost in the \$50 to \$200 range. The better quality sorobans will provide smooth moving beads and touch ergonomics that help build physical speed. For a beginning student, we recommend a low cost 15 or 17 rod plastic abacus. Students can always upgrade their abacus as they advance their math training.