- By Gaurav Tiwari
- Study Notes,Research,Recreations,Real Analysis,Problems,Number Theory,Math
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Multiplication is probably the most important elementary operation in mathematics; even more important than usual addition. Every math-guy has its own style of multiplying numbers. But have you ever tried multiplicating by this way?
Exercise: $ 88 \times 45$ =?
Ans: as usual :- 3960 but I got this using a particular way:
Thus, $ 88 \times 45=3960$ (as usual).
You might be thinking that what did I do here. Okay, let we understand this method by illustrating another multiplication, of 48 with 35.
Step 1. Write the numbers in two separate columns.
$ 48 \\ 35$
Step 2. Now, double the number in left column and half the number in right column such that the number in right column reduces to 1. If the number [remaining] in right column is odd, then leave the fractional part and only write integer part.
$ 48 35 \\ 96 17 \\192 8 \\ 384 4 \\ 768 2 \\ 1536 1$
Step 3: Cancel out any number in the left column whose corresponding number in the right column is even.
Step 4:Sum all the numbers in the left column which are not cancelled. This sum is the required product.
I agree this method of multiplying numbers is not easy and you’re not going to use this in your every day math. It’s a bit boring and very long way of multiplication. But you can use this way to tease your friends, teach juniors and can write this into your own NOTEBOOK for future understandings. Remember, knowing more is getting more in mathematics. Have Fun.