Did you forget how to divide?

Did you forget how to divide?

17/04/2020

Recovered from Medium

Let’s make an easy example to get it.

How do you divide this? Well… divide and conquer.

The order doesn’t matter, so you could divide where 17 (the divisor) fits best. Now subtract 17x1 by writing it above and the remainder below.

The result of 171717 divided by 17 is 10101, that is all.

Let’s make another example; 6485927/3. First, group in known divisors:

Notice 27 could be easily divided by 3x9=27. So, continue dividing individually, keeping vertical alignment. Write the individual remainder below.

Repeat the process:

Finally, add the quotients:

The result of 6485927/3 is 2161975+2/3=2161975.6666…

This could be faster when the dividend has many individual groups with obvious divisors like 171717. However, the traditional process could be messy if you constantly change between add, carrying, multiplication, and subtraction. This way you keep the sum and the carrying at the end avoiding the switching that could be less mnemotechnic.

It could be harder with greater divisors, for those cases you should write apart the main multipliers, e.g if the divisor is 132, then write down the result of 132x2, 132x3, 132x4,… as much as you need. Like it was in the example if you don’t know that 27 could be grouped then just divide and conquer.