### Vedic Math - Multiplication of numbers with a series of 1's

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In the previous article, we learnt the technique of "how to multiply numbers with a series of 9’s". In this article, we shall learn the technique of "how to multiply numbers with a series of 1’s". So, we shall multiply the numbers with 1, 11, 111,..... etc.

In this technique, we use "vertically and crosswise" vedic sutra. Take example of ab x uv, and apply the sutra as follows:

a         b
u         v
---------------------
a x u | av + ub | b x v
---------------------

(Here '|'  is used just as separator)

Here we are splitting the answer in three parts as following:
• vertically                         =(b x v)
• crosswise multiplication and add   =(a x v) + (b x u)
• vertically                         =(a x u)
During multplication with 11, u=1 and v=1, means:

a               b
1               1
--------------------
a  |  a + b  |  b
--------------------

Example:  Multiply 53 by 11