Multiply by 21, Another method

As I promised you in my previous article, another method of multiplying by 21

Rule is Prev. digit + twice of next digit ( Carry over if required )

Let us take an example  456 X 21

Apply the rule from left to right

0 + 2 X 4   = 8 ( Since there is no previous digit for four, we added zero )

4 + 2 X 5 = 14

5 + 2 X 6 = 17 

The last digit is same as the last digit in the problem ( 456 ), so it is 6.

Let us write it together.

8 |  14 | 17 | 6, we have to apply carry over.

     

              So the answer is :   9576

Check the answer with your calculator, soon you may not need that.

This method can be applied for any number, however big it is !!!!!!

Enjoy doing maths !!!!!

Please Note : | symbol is used here as partition, no other special meaning.

Add fractions in seconds

Having a nightmare with fraction manipulation, here is an easy and natural solution for doing it.

Let us take,

3          4

---  +   ----    =       Multiply Crosswise and add  ( 3 X 6 = 18  and 5 X 4 = 20,

5           6                                                               that makes 18 + 20 = 38).

( In Maths terms   Multiply Left Numerator By Right Denominator and vice verse)

So Top of the answer is : 38 (Numerator)

For calculating bottom of the answer simply multiply both the numbers in bottom (5 X 6= 30). (Denominator)

So the answer is 38

                           ------

                            30.

If you want to subtract ? instead of adding both numbers to figure out the top of the answer (Numerator), just subtract.

Isn't simple enough ?

Multiplying two numbers ending with 5

There is a easy and quick way to find out the product of two numbers ending with 5.

Let us take an example

45 X 85

 
Step 1 : 4 + 8 = 12 ( Sum of the digits of two numbers leaving the last digit)
Since 12 is an even number write 25 in the answer.

                                  Step 2 : 4 X 8 = 32  

                                 Step 3 :  (4+8)/2 = 6 ( Since the sum is         the even number we divide it by 2)

Step 4 :   32+6= 38

Write it together 3825.


Let us take another example

35 X 85

Step 1 : 3 + 8 = 11
              Since the sum of first two digits are odd write 75 in the answer.
Step 2 : 3 X 8 = 24

Step 3 : (3+8-1) / 2 = 5 ( Since the sum is the odd number, we deduct -1)

Step 4 : 24 + 5 =29

Write it together 2975

How Vedic is Vedic Maths ?

How Vedic is Vedic Maths ? - Myths and Facts

            There are so many articles in Internet available which says Vedic Maths is not really from Vedha. If you go thru the articles keenly you will find something common in all the article.

They don't disagree that Vedic Maths techniques are correct and effective.

They only disagree that hype given to Hinduism or Knowledge of Hinduism in the means of Vedic Maths. 

Another common criticism about Vedic Maths is instead of following one single Common pattern of calculating, why should a child learn so many Techniques and apply differently based on situations ?

Then so many of my friends asking me why to use these methods, when we have calculator and computer to do the same ?

Initially I felt these comments are absolutely correct.  But after practicing it for sometime, I started understanding the difference.

Let us take the first complaint, Is it really from Vedha ?

Why do we need to worry whether it is from Vedha or not, if it is going to help a child to calculate fast, if it is going to build the mental strength of the next generation, why not we follow and teach it to the children ?

Next thought, when there is a conventional proven method, why to go for a complex confusing one ?

But people can find the difference only after practicing it.  For last nearly 30 years I was practicing the conventional method, very comfortable and happy with that, but it does not require my mind to work in any calculation, we had memorized tables and formulas in our child hood, learned some methods to apply that in add / sub / multi / div. So even while watching TV, enjoying the music, listening a gossip still I can do the sums. 

I cannot think of doing vedic maths with that environment, it requires absolute creativity to use the same formulas in different situation, simultaneously I have to do the calculation to give the answer in seconds ( At least in minutes). It gives immense exercise  to mind, to keep it healthy and fit.

This mental health would be useful for us in different situation to solve any problems, not only Maths.


Third common point of view is, why to do manually when we have machines to do so ?

    Yes, we have so many machines in our daily life, to make our task easy and leads to unhealthiness. So we go to gym and give exercise to our body parts to keep it fit. We can take Vedic Maths like that also, mental gym to keep the mind cells active.

However I found so many institutes offering Vedic Maths to children under the age of 12... In my point of view that is really not advisable. Unless a child is absolutely comfortable with the Basics, it is not good for a child to learn the Techniques.

Multiply by 21

Multiply any number by 21 in seconds

Very very simple and convenient method to multiply any number with 21.

Take the example of 45 X 21

First multiply 45 X 20 = 900
           Add 45                   45
                                        ------
                                        945

Take 567 X 21

Step 1 : 567 X 20 = 11340
Step 2 :                 +     567
                                ----------
                                 11907
                                ----------

The same method could be extended for 31, 41, 51.... etc multiplication as long as a child is comfortable in Tables.

However this method will not be effective as the no. of digits in the first number increases ( If a child is comfortable enough, you can use this).

We can use another method which is related to multiplication of 11, will be discussed in next post.

Dividing by 9

 

Simple mental method to divide a number by 9.

Take any number, say 15

15 / 9 = Write the first no. as quotient  Q - 1

                                                      reminder is 1 + 5 ( Add the digits) 6

                                                     So answer is Q=1 Reminder=6

Let us take another example with a little variant, say 48

 48 / 9 =  Write the first no. as quotient   Q= 4

                

reminder is 4 + 8 = 12

Since 12 has 9 one time, add the 1 with Q (4+1)

So Q= 5, Reminder = 12 - 9 = 3

Q = 5, R= 3.

Let us see, how it works with 3 digits,  example 567

567/9 = Write the first no. as quotient   Q=5

Then add 5 + 6 = 11, that is the second no. in the answer, since 11 is a two digit number, 1 should be carried to the previous digit.

5+1 1 That is 61 (Q)

Then for the reminder add all the digits (5 + 6+7) = 18.

Since 18 has 9 two times, add 2 with 61(Q).

So the answer is Q=63, R=0.

The same method can be carried out to any number of digits, with a little practice of carry concept.

Find the square of the number ending with 5

Finding square of the Number ending with 5 ( Any number )

Simple and easy method to find the square of the number ending with 5.

For Ex. given no. is 75

Multiply the first no with the consequent no. i.e. 7 X 8 = 56

Multiply the last no. with the same                 i.e. 5 X 5 = 25

Write it together 5625. 

Let us try with 345

34 X 35          5X5

119025   Check with your calculator......... Same method can be applied to any number ending with 5.

( How to multiply 34 X 35 easily... that is another formula....)

Calculating Complements (10's)

Recollect the concept of complements what we learned in our school times !!!!
We take a base number (Ex.10 or 100), and subtract the given number to find the complement. Same Concept with a different technique.

Just follow the formula (Subtract) All from Nine and the last from 10.

Take any number, for Ex. 675

(9-6)(9-7)(10-5)= 325 is the answer.

Is in it easy ? here we don't have to worry about the no. of base or the no. of digits in the given number... just apply the rule and get the results......

Multiplying by 11

 MULTIPLY any number BY 11 - Find the answer in seconds

To multiply any number by 11 do the following:
Working from right to left

1. Write the rightmost digit of the starting number down.
2. Add each pair of digits and write the results down, (carrying digits where necessary right to left).
3. Finally write down the left most digit (adding any final carry if necessary).
   

It's as simple as that, e.g.

• Multiply 712x11
  

Digit1        Digit2         Digit3           Digit4

7             7+1            1+2               2

first no.     Sum of        Sum of            Last no.

               I and II      II & III 

So it is  712x11=7832

Another Example 

Multiply 8738x11

8   8+7     7+3   3+8    8

8    15      10    11    8 ( Now let us carry over the sum,

                              since we are getting 2 digits in the sum)

9    6        1    1    8  So the answer is 

 8738x11=96118

Is in it Simple ?

Try with other nos and see........

Adding Time using ancient menthod

 

Here is a nice simple way to add hours and minutes together

Let's add 5 hrs and 45 minutes and 2 hrs 35 minutes together.
What you do is this:

make the 5 hrs 45 minutes into one number, which will give us 545 and do the same for the other number, 2 hours 35 minutes, giving us 235
Now you want to add these two numbers together:

545
235
____
780

So we now have a sub total of 780.
Add the time constant of 40 with the subtotal.

No matter what the hours and minutes are, just add the 40 time constant to the sub
total.
780 + 40 = 820
so we can now see our answer is 8 hrs and 20 minutes!

Watch Out for more tips....

What is vedic Maths ?

Having Problems with Maths ?  Here is an ancient solution.

   
Vedic Maths is an old system of Indian Maths, which was extracted from the Vedas during the period from 1911 to 1918 by Sri Bharati Krishna Tirthaji.  According to him all the maths problems can be solved using the  Sixteen Sutras and 16 Sub Sutras (formulas).  These sutras helps us to perform the math operation in the same way our mind naturally works therefore it is easy for a scholar to do the operation without much effort.

These sutras are all understandable easily.  It makes learning of mathematics easy,  enjoyable and encourages innovation. 

Jagatguru Sri Bharati Krishna Tirthaji

The beauty of this system is, we can invent our own methods, there is no "one perfect" method to solve the problem. This leads to more creative, interested and intelligent younger generation.

The operations are  based on 16 formulas or aphorisms, which are actually word-formulae for the whole range of mathematical problems.  These 16 one-line formulae originally written in Sanskrit, which can be easily memorized, enables one to solve complex problems quickly.  The wonderful thing in this formulas are, they are not fixed for a particular kind of problem, each and every formula can be used in ennumber of ways based on the type and complexity of the problem and creativity of the person using it.

Let every child learn our ancient system to improve their speed, creativity.