The Abacus

Salam,

I've never used abacus in my life but now I have to learn how to use or at least learn about it. WHY? My elder daughter has started to learn using abacus in school during Mathematics. She knows how to use it. The problem is sometimes she still depends on me to help her with her homework.

Have you ever used it? Do you know how to use it? Are you good at it?

When I tried to find some information about abacus, I found out that the different types of abacuses. I found interesting things about the Japanese Abacus (Soroban) and Chinese Abacus. I also found how to use them. Would you like to know how to use them too?

The Abacus

© Copyright 1998, Jim Loy
On the left, you see two abacuses (abaci is also correct). On both abacuses, we see the number 1998. The top area of each abacus is used for fives, and the bottom area is used for ones. Abacuses are used for doing arithmetic. When doing arithmetic, you move the beads. The position of the beads represents the sum, or product, so far. It is how you can remember the partial sum or product. Experts in the use of the abacus can be very fast (and accurate), often faster than an expert with a calculator, especially addition and subtraction. Such an expert on the abacus is especially adept at data entry.
In the original version of this article, I mistakenly had the top area of the two abacuses upside down. To start out, the abacus registers zero, with the bottom (ones) beads all the way down, and the top (fives) beads up.
I won't get deeply into the mechanics of using an abacus. Let me just say, to add one to a number, you either move a bead (in the rightmost "ones" column) up, or move all four beads down then execute a carry into the "fives" area. This carry just involves moving the five bead down (remember that up is a zero and down is a five), or moving it up (to zero) then executing a second carry into the "tens" column.
The Japanese abacus, the soroban, is more elegant, as the Chinese abacus has redundant beads. With the Chinese abacus, you never have to use the bottom bead in each column, in both the "ones" and "fives" areas. These extra beads are apparently useful, if you use an extra step every time you carry. You notice that you have all five beads up, so then you know you should execute a carry. 


Is it complicated? Do you understand how to use them now? I guess you'll be better after some practice. With the knowledge, I reckon at least I can help and have some ideas how to help Fathini in using abacus.