One powerful Vedic math shortcut is called crisscross multiplication. Another is a trick for finding the squares of numbers that end in 9, and a third is a shortcut for quickly multiplying any number by multiples of 11, such as 22 or 88. All of these systems allow the user to calculate math problems quickly and, in many cases, without using any form of writing.
The crisscross system of multiplication is an alternative way of multiplying two-digit numbers together. A simple example includes multiplying 12 by 34. The first step is to multiply both of the one digits by each other, in this case the 2 and the 4. The answer, 8, is the ones digit of the final answer. The second step is to multiply the tens digit of the first number by the ones digit of the second number and vice versa. In this case, 1 (the tens digit of 12) multiplied by 4 (the ones digit of 34) equals 4, and 3 (the tens digit of 34) times 2 (the ones digit of 12) equals 6. The sum of the two products, 4 and 6, is 10. The 0 from 10 is the tens digit in the final answer, and the 1 needs to be carried over. The third and final step is to multiply the two tens digits. In this case, 1 times 3 is 3. Three is added to the 1 that was carried over from the previous step to get 4, the hundreds digit of the final answer. The final answer of 12 times 34 is 408.
With additional steps, this method can also be used for multiplying numbers of three or more digits.