How to divide 2 numbers

To make a division on the soroban, we also use an analog of the long division algorithm you may already know. You need to know your multiplication table [Wikipedia], and also how to perform subtraction on the soroban.

We want to divide a dividend de by a divisor do, to get a quotient q and a remainder r.

Very simple division

Let's try with a very simple division, first, to get the basic idea: 7 / 3.

We put the dividend 7 on the center of the soroban. Then let 4 empty rows on the left, and put the divisor 3(left image).

How many times will 3 go into 6 ? 2, so we put 2 on the soroban at the left of the dividend by letting one emtpy column.

We know multiply 3 by 2 and subtract the result 6 from 7, which left us with 1(right image).

So the quotient is 2 with a remainder of 1.

A one digit divisor division

Let's do something a little more complicated with a division with a dividend with multiple digits but still one digit for the divisor: 945 / 5.

How many times 5 will go into 9 ? 1 so we put 1 at he left of the 945. And then subtract 5 from 9; we are left with 4 on that column(right image).

We will have to repeat the process until the remainder is less than the divisor. So, for now, the remainder is 445 and way greater than 5, so we continue.

How many times 5 will go into 4 ? None, so we add a digit of the dividend and consider how many times 5 will go into 44 ? 8 so we put 8 at the right of 1, and at the left of the remainder, and then subtract 8 * 5 = 40 from the remainder. We are left with 45(left image).

How many times 5 will go into 45 ? 9, so we put 9 on the soroban at the right of 18, and then subtract 9 * 5 = 45, and we are left with a remainder of 0(left image).

So the quotient is 189 with a 0 remainder.

A division