Vedic mathematics is a system of mental calculation developed by Shri Bharati Krishna Tirthaji in the middle 20th century.

Here is an example of the vertical and crosswise formula.

43 x 92 = 3956

When one of the results contains more than 1 digit, the right hand digit is written and the left hand digit or digits is carried over.

43 X 92

Step 1 : 3 X 2 = 6

Step 2 : 4 X 2 = 8;   9 X 3 = 27;   8 + 27 = 35    Here 5 is retained and 3 is  carried over to the left side.

Step 3 : 4 X 9 = 36. Now the carried over digit 3 of  35 is  added to 36.    Example : 36 + 3 = 39

Thus 43 X 92 = 3956

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