Faster and accurate calculation of data is very important in solving DI questions. While solving questions in the exam, pressure is very high and so accurate calculation of results is very necessary.
Vedic Maths is one such way in which an aspirant can do calculations in a much faster and easier way to achieve accurate results.
To begin with Vedic Maths, first find the square of 94. If you calculate the result by normal calculation, you would require about 10 seconds to find the result. Now see this…
What is the difference between 100 and 94. Its 6. Subtract 6 from 94 and the result is 88. Find square of 6 and write it with 88. The result is 8836. Isn’t this the square of 94?
Well that was quick. 
Now find the square of 91?
Difference between 100 and 91 is 9 and subtract 9 from 91 = 82 and write square of 9 (which is 81) with 82 and answer is 8281.
100 – 91 = 9
91 – 9 = 82, Multiply 82 with 100 = 8200 ——— (i)
9 * 9 = 81 ———— (ii)
Now add (i) and (ii)
8200 + 81 = 8281 which is the square of 91.
Here we have taken 100 as the base ( a base is a number with respect to which we are doing our calculations). Any number can be a base. Lets take 93 as a base to calculate square of 91.
93 – 91 = 2 ( Here the difference is 2. Subtract the difference from the original number)
91 – 2 = 89. Now multiply this number with the base. 89 * 93 = 8277 ————— (i)
Find square of 2 = 4 and add it with (i). The result is 8277 + 4 = 8281
The result is same but in this case the calculation is a bit difficult and so we generally take 100 as base. Now calculate square of 102. Difference is -2 and subtract -2 from 102, the result is 102 – (-2) = 104 and multiply it with base 100 = 104*100 = 10400 and add square of (-2) and so the answer is 10404.
For numbers like 989, we can take 1000 as a base to find the answer.
But what do we do for numbers like 46? In this case we take base 50 and subtract the difference from the number.
50 – 46 = 4, 46 – 4 = 42. Now multiply this number by 100 and divide it by 2 ( you can simply multiply with 50). (42 * 100)/2 = 42 * 50 = 2100. Now add square of 4 = 2116.
Similarly take 500 as base for numbers like 492.
Thus we can easily and accurately calculate squares of numbers.
Now lets study another concept. In case we have to multiply two numbers ( like 24 and 26) whose units digit when added equals 10 ( 4 + 6 ), the answer can be found by multiplying the units digit and multiplying the tens digit with the next number and write the two numbers together.
Lets find product of 24 * 26. The sum of units digit is 10 and 4 * 6 = 24. Multiply 2 ( the tens digit of both numbers ) with the next integer ( which is 3). 2 * 3 = 6 and write the two numbers together, 624.
Find product of 63 and 67. Multiply units digit ( 3 * 7 = 21) and tens digit with the integer which comes after it, which is 7 in this case. ( 6 * 7 = 42). Now write the two numbers together to form the answer, i.e, 4221. Therefore, 63 * 67 = 4221.
For finding square of a number ending with 5, we can take the number as the product with itself. For e.g square of 45 can be written as 45 * 45. The units digit add to form 10 and so we can apply the concept we learnt just now.
5 * 5 = 25 and 4 * 5 = 20. Therefore, the answer is 2025.
Lets find square of 85. We will find the answer by both the methods discussed above.
Method 1
Take 100 as base. 100 – 85 = 15. Subtract 15 from 85 = 70 and now find square of 15 = 225. Multiply 70 with the base = 7000 and add 225 to 7000 = 7225.
Method 2
Square of 5 is 25. Multiply 8 with its next integer ( which is 9 ) = 72. Write both the numbers together = 7225.
Both the methods give answer 85 * 85 = 7225. Thus, we have now discussed 2 methods which help us to make calculations faster and easier.
You can practice some questions written below.
1. 115 2. 93 3. 38 4. 992 5. 106 6. 487