An Alternative Method to Help with Division
In today’s post we’re going to look at an alternative method of division. Schools often tend to teach the standard algorithm, but that’s not the only way of doing it. Once a child learns how to divide using the classic algorithm, there’s no need for them to use any alternative. The objective is to calculate the quotient of a division, and knowing how to do it one way is sufficient.
However, the objective of this post is to expand the frontiers of everyday mathematics and hopefully learn something new and interesting.
This method is known as “Russian division”. It originated in ancient Egypt as a multiplication method, as we’ll see in the following example.
We’re going to divide 1860 by 25:
This method is based on doubling multiples of the denominator until we find the highest multiple smaller than the numerator. In this example, we’ll double multiples of 25 until we find the one before 1860. We’ll go through it step by step.
First we multiply 25 by 2 and then the result, which is 50, by 2 again.
We keep doubling the multiples until we get to 1600, which is the last multiple of 25 less than 1860.
Once we’ve got this pair of numbers we need to find a way to find the closest number to 1860 by adding the numbers from the column on the right.
In this case, 1600 + 200 + 50 = 1850
Now we need to add the numbers from the left that correspond to the numbers we’ve chosen on the right.
So, 2 + 8 + 64 = 74
The number we’ve just calculated with this last sum… Is the quotient of the division!
And to work out the remainder, we just need to subtract 1850 from our dividend. 1860 – 1850 = 10
We’ve solved the division! As you can see, it’s not a particularly complicated or difficult method, but it’s 100% effective.
I hope you’ve found the method in this post as interesting as I did! Isn’t it great to learn something new? If you want to keep practicing primary mathematics online, you can log in to Smartick and enjoy our method.