# Trachtenberg System

- 1 min

I just finished watching a movie called Gifted. It came out in 2017 and was in my watchlist since a long time.

Movie begins with Frank ( Chris Evans ) and Mary, his niece. Mary is a genius who is highly skilled in mathematics. She is just seven and still way ahead of other children of her age.

There is a scenario in a movie where she solves big multiplications. She does this without using any calculator or writing down the steps leaving her teacher amazed. Later Frank reveals to her teacher that it is a Trachtenberg’s method.

So i searched the internet about the method. Here is what i found,

Trachtenberg’s method helps you to perform big number calculations rapidly using some techniques. It is called as a system of mental calculation. It consists of numerous readily made operations that can help you compute very quickly.

It was developed by the Russian Jewish engineer Jakow Trachtenberg. He designed various algorithms for addition, multiplication as well as division.

It is similar to vedic mathematics which was designed by elite mathematicians.

Let us take an example where we multiply 492 x 2. This can be done as follows,

To multiply by 2, multiply each digit by 2 (with carrying), from right hand side. eg. 492 x 2:

1. 4 + 4 = 8,
2. 9 + 9 = 18 (carry is 1),
3. 2 + 2 = 4 Write down all digits from RHS from bottom to top i.e from step 3 to step 1.
4. We get 4 - - 8 - - 8 + 1 (carry) = 9.
5. Reverse the result and the final answer is 984.

492 x 2 = 984