pocket abacus

Step 9 How to divide

Dividing on the abacus is a little more difficult, however is really just multiplication in reverse.

division vocabulary:
dividend: number to be divided
divisor: number to be divided by
quotient: result of the division

As with multiplication, we can count the numbers in the equation to figure out which column to start on the abacus. With multiplication we added the multiplicand digits with the multiplier, with division we take away dividend from the divisor.

In this example:       
                                      8965 / 5
The dividend has 4 digits and the divisor has 1.
The trick with division on the abacus is to add 1 to the total to know how many columns we will use.
4 (dividend) - 1 (divisor) +1 (abacus rule of division) = 4, this is how many digits will be in our quotient.

With multiplying, I used the abacus to keep track of the multiplicand. In division, I only keep track of the divisor (on an empty left column) and remainders from division (on an empty right column). For this reason I use the middle of the abacus to compute.
Start from left to right dividing 5 into 8 which is 1, keep track of the remainders on an empty column on the right (in this case 3. Next take that remainder as the first digit and use 9 (the second number in our dividend) and you have 39, now divide 5 into 39 to get 7 remainder 1. Continue this process over until you exhaust your dividend and you will have your answer.