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October 10th, 2009, 11:45 AM   #1
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Vedic Maths - Tricks to do fast mental calculations

Vedic Maths - Trick 1

Use the formula ALL FROM 9 AND THE LAST FROM 10 to perform instant subtractions.

* For example 1000 - 357 = 643

We simply take each figure in 357 from 9 and the last figure from 10.

So the answer is 1000 - 357 = 643

And thats all there is to it!

This always works for subtractions from numbers consisting of a 1 followed by noughts: 100; 1000; 10,000 etc.

* Similarly 10,000 - 1049 = 8951
* For 1000 - 83, in which we have more zeros than figures in the numbers being subtracted, we simply suppose 83 is 083.

So 1000 - 83 becomes 1000 - 083 = 917
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October 10th, 2009, 03:01 PM   #2
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This is essentially the normal way in which change is calculated mentally.
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October 11th, 2009, 02:26 AM   #3
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Re: Vedic Maths - Tricks to do fast mental calculations

Vedic Maths - Trick 2

Using VERTICALLY AND CROSSWISE you do not need to the multiplication tables beyond 5 X 5.

* Suppose you need 8 x 7

8 is 2 below 10 and 7 is 3 below 10.
Think of it like this:

The answer is 56.
The diagram below shows how you get it.

You subtract crosswise 8-3 or 7 - 2 to get 5,
the first figure of the answer.
And you multiply vertically: 2 x 3 to get 6,
the last figure of the answer.

That's all you do:

See how far the numbers are below 10, subtract one
number's deficiency from the other number, and
multiply the deficiencies together.
* 7 x 6 = 42

Here there is a carry: the 1 in the 12 goes over to make 3 into 4.

Here's how to use VERTICALLY AND CROSSWISE for multiplying numbers close to 100.

Suppose you want to multiply 88 by 98.

Not easy,you might think. But with
the answer immediately, using the same method
as above.

Both 88 and 98 are close to 100.
88 is 12 below 100 and 98 is 2 below 100.

You can imagine the sum set out like this:

As before the 86 comes from
subtracting crosswise: 88 - 2 = 86
(or 98 - 12 = 86: you can subtract
either way, you will always get
the same answer).
And the 24 in the answer is
just 12 x 2: you multiply vertically.
So 88 x 98 = 8624
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October 11th, 2009, 05:53 AM   #4
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Re: Vedic Maths - Tricks to do fast mental calculations

Tricks of the trade are worth a mention; we all have a few up our sleeves after a few years of application. It might also be worth mentioning that they are most often gleaned, and most often used after there has been some initial mastery of age-tested procedures more suitable for the very young, who are seeing it for the first time. Too often, in the present classroom, I've seen he results of people who learned procedures that had a limited application, then stumble as the problems became a bit more complex. What is really important is a firm foundation that has application in later study. The learning processes differ widely depending upon how a problem is approached in the beginning. Old habits can make new, necessary habits more difficult. Hindsight is wonderful, but let us not forget how we learned, and learned quite well, and it is that which enables us to not just memorise, but understand a different application such as this and why it works. Some memorisation is important in the beginning. We learned our times tables by rote well before grade 2. I've seen children today in grades 7-9 not knowing that, but having been exposed to several other processes, such as rolling dice for problems in elementary probability [not named as such so as to no confuse them.] As a result, they were not fully prepared for what was to come.

So, lets' just be a little careful here, please, in assessing the value of some particular process.
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June 5th, 2014, 08:16 AM   #5
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Thanks for providing these very useful vedic maths tricks. Can you post something on division
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