Soroban abacus tutorial pdf

Community

It’s a useful learning device for the visually impaired, as well as for anyone who wants to learn the roots of the modern calculator. After learning the basics of counting on the abacus, you can quickly perform arithmetic like addition, subtraction, multiplication, and division. Each column in the top row should have one or two beads per row, while soroban abacus tutorial pdf column in the bottom row should have four. When you start, all of the beads should be up in the top row, and down in the bottom row.

The beads in the top row represent the number value 5 and each bead in the bottom row represents the number value 1. Assign each column a place value. As on a modern calculator, each column of beads represents a “place” value from which you build a numeral. For example, if you are representing a number like 10. Likewise, to represent a number like 10.

25, the furthest right column would be the hundredths place, the second column would be the tenths place, the third the ones place, and the fourth the tens place. Start counting with the beads in the lower row. To count a digit, push one bead to the “up” position. One” would be represented by pushing a single bead from the bottom row in the farthest column on the right to the “up” position, “two” by pushing two, etc. Since there are only four beads on the bottom row, to go from “four” to “five,” you push the bead on the top row to the “down” position and push all four beads from the bottom row down. The abacus at this position is correctly read “five.

Repeat the pattern for higher numbers. The process is essentially the same across the abacus. Two hundred and twenty six would have two in the third column pushed up in the bottom row, and two in the second column pushed up in the bottom row. In the first column, one bead on the bottom row would be pushed up, and the bead on the top row would be pushed down. Say you’ve got to add 1234 and 5678. Enter 1234 on the abacus by pushing up four beads in the ones place, three in the tens place, two in the hundreds place, and one in the thousands place. The first numbers you’ll add are the 1 and the 5 from the thousands place, in this case moving the single bead from the top row of that column down to add the 5, and leaving the lower bead up for a total of 6.

Likewise, to add 6 in the hundreds place, move the top bead in the hundreds place down and one bead from the bottom row up to get a total of 8. Since adding the two numbers in the tens place will result in 10, you’ll carry over a 1 to the hundred place, making it a 9 in that column. Next, put all the beads down in the tens place, leaving it zero. In the ones column, you’ll do essentially the same thing.