Add & Subtract Method
Rules:This method is based on selecting a proper base and then using the Vedic maths method to calculate. Selecting a proper base is one of the most important things in this method, which makes major calculations very simple. See the example of different bases and make sure you use your wits to choose a proper base while calculation. It works in the following manner.
9 x 9
9 – 1 [ We assume the base as 10 ]
9 – 1
8 /1
Steps involved:-
We select the base as 10.
Then we check the difference for each number as compared to 10. In this case the difference is -1. So we write -1 on the right on side of this number.
Then we multiply the right hand side. In this case -1 x -1. So we get 1 as the answer.
Then we do cross addition/subtraction. In this case we would subtract -1 from the number 9 and then we get the answer as 8. And the final answer as 81.
9 x 8 [ We assume the base as 10 ]
9 – 1
8 – 2
7 /2
Steps involved:-
We select the base as 10.
Then we check the difference for each number as compared to 10. In this case the difference is -1 & -2. So we write -1 & -2 on the right on side of these numbers respectively.
Then we multiply the right hand side. In this case -1 x -2. So we get 2 as the answer.
Then we do cross addition/subtraction. In this case we would subtract -2 from the number 9 or we subtract -1 from the number 8 and then we get the answer as 7. And the final answer as 72.
11 x 12[ We assume the base as 10 ]
11 + 1
12 + 2
13 /2
Steps involved:-
We select the base as 10.
Then we check the difference for each number as compared to 10. In this case the difference is +1 & +2. So we write +1 & +2 on the right on side of these numbers respectively.
Then we multiply the right hand side. In this case +1 x +2. So we get 2 as the answer.
Then we do cross addition/subtraction. In this case we would add +2 from the number 11 or we add +1 from the number 12 and then we get the answer as 13. And the final answer as 132.
It is simple, isn't it?
91 x 91 [ We assume the base as 100 ]
91 – 9
91 – 9
82/81
Steps involved:-
We select the base as 100.
Then we check the difference for each number as compared to 100. In this case the difference is -9 & -9. So we write -9 & -9 on the right on side of these numbers respectively.
Then we multiply the right hand side. In this case -9 x -9. So we get 81 as the answer.
Then we do cross addition/subtraction. In this case we would subtract -9 from the number 91 and then we get the answer as 82. And the final answer as 8281.
Now, we have moved on to higger numbers too.
You may practice higher numbers like 120 x 102 or 105 x 108. But remember so far our base has only been 10 & 100. We will move on to slightly complex task tomorrow. You may check the next few examples. Solution is not given, but by now you should be used to doing these simple calculation mentally.
888 x 998 [ We assume the base as 1000 ]
888 – 112
998 – 002
886/224
598 x 998 [ We assume the base as 1000 ]
598 – 402
998 – 002
596/804
PRACTICE PRACTICE PRACTICE!!!
