Two digit multiplication in 3 seconds

Merry X-Mas to every one!!!
                                -RCR


How to do multiplication from 10 x 10 to 20 x 20.

Try to do following examples and note the time to get the answer.

Ex 1 : 14 x 11 = ?
Ex 2 : 16 x 12 = ?
Ex 3 : 18 x 13 = ?

Now lets try using the trick. First let me explain the trick.

Ex 1 : 14 x 11 = ?

This is multiplication with 11. Did you remeber the trick which was discussed in previous post?

1's digit   : 4
10's digit :  1 + 4 = 5
100'digit :  1

So the answer is  154.

Now I am going to explain trick which is useful for multiplication from  10 x 10 to 20 x 20.

Ex 1 : 14 x 11

Instead of explaining the trick by me, just watch the video

Now you try multiplying the same numbers again and note the time.

Just an improvement to the method mentioned in the video.

Ex 2 : 16 x 12 = ?
       
1's digit : 6 x 2 = 12
10's digit : 16 + 2 = 18

So answer is 192 ( 1 in 12 carry forward to 10's digit )

Ex 3 : 18 x 13 = ?

1's digit : 8 x 3 = 24
10'digit : 18 + 3 = 21

So answer is 234 ( 2 in 24 carry forward to 10's digit )

Multiplication by 11

Leadership and learning are indespansable to each other  
                                                                           - John F Kennedy

Note:  All these tricks applicable for below 100. We can extend these tricks to above 100 with slight modification  in the formula. Some tricks applicable without modifications also.

Let me recall tricks for multiplication with 5 and 9

Ex : 48 x 5 = ?
       step 1 : 48 / 2 = 24
       step 2 : 24 x 10 = 240
       Therefore 48 x 5 = 240

Ex : 48 x 9 = ?
 From now onwards we will follow the following notation :     
 .../1000's digit / 100's digit/ 10's digit/ 1's digit

So 48 x 9

1's digit         : 10 -8 = 2
10's digit       :  48 - 4 - 1  = 43
In the result (43)  10's digit is 3
4 becomes 100's digit

Therefore 48 x 9 = 432

If you have any confusion, please refer the formula in previous post.

Multiplication with 11 :

11 table song 


This is very easy. Multiplication by 11 is adding the digits in the number.

Lets see how this works 

Ex1 : 23 x 11 = ?

Remember the notation as I mentioned above 
 
1's digit : 3
10's digit : 2 + 3 = 5
100's digit : 2

So 23 x 11 = 253

Ex2 : 49 x 11 = ?
1'digit : 9
10's digit : 4 + 9 = 13
100's digit : 4

So 49 x 11 = 4 / 13 / 9
                  = 539 ( 1 carry forward to hunderds in 13. so 4 + 1 = 5 )

Ex3 : 54 x 11 = ?

Ex4 : 74 x 11 = ?

Practice above examples.

Happy Learning ...

    

Anyone who stops learning is old, whether at twenty or eighty. Anyone who keeps leanring stays young. The greatest thing in your life is keep your mind young.

- Henry Ford

Lets take a look at tables or multiplication with single digit. Try to remember tables upto 10 helps you for quick calculation.

Table 2 : doubling or making half of a number is easy for anyone. Thats why learners prefer doubling a number while multiplying with 2
Table 4: Double number two times
Table 8: Double number 3 times
Table 3, 6, 7 : you have to remember these tables to do multiplication with these number

Only two tables have tricks to do multiplication in 1 to 10. Those are 5 and 9.

Table 5 or multiplication with 5 :  

Ex 1 :  6 x 5 = ?

Ex 2 : 12 x 5 = ?

Ex 3: 21 x 5 = ?

Trick : 1. make half of the number
            2. multiply the result with 10 

Lets take first example i.e 6 x 5 = ?

1. Make half of the number i.e half of the 6 = 3
2. multiply the result with 10 i.e. 3 x 10 = 30

Try Ex 2.

Ex 3 : 21 x 5 = ?
1. Make half of the number i.e half of 21 is 10.5
2. multiply the result with 10 i.e. 10.5 x 10 = 105.0 = 105


Table 9 or multiplication with 9 :

Ex 1 : 7 x 9 = ?
Ex 2 : 16 x 9 = ?
Ex 3 : 19 x 9 = ?

Trick : 
1. 10 - one's digit ( subtract one's digit from 10 )
2. Number -  1 - ten's digit in number

Lets take first example i.e 7 x 9 = ?

1. one's digit ie 7. So 10 - 7 = 3
2. Number is 7. So 7 - 1 - 0 = 6 ( There is no ten's digit in 7. So it is 0 )

Therefore 7 x 9 = 63

Try Ex 2.

Ex 3 : 19 x 9 = ?

1. one's digit is 9. So 10 - 9 = 1
2. Number is 19. So 19 - 1 - 1 = 17

Therefor 19 x 9 = 171

Let try one more example. 97 x 9 = ?
1. one's digit is 7. So 10 -7 = 3
2. Number is 97. So 97 -1 - 9 = 87

Therefore 97 x 9 = 873

Happy learning...

Multiplication tricks

Quote  : Develop a passion for learning . If you do, you will never cease to grow.
-  Anthony J. D'Angelo 

we will discuss most frequent operation in calculations i.e.  multiplication

what is multiplication?
multiplication is nothing but repeated addition.

Ex 1: 
2 x 3 = ?
2 + 2 + 2 = 6 or 3 + 3
2 adding 3 times is 6, i.e. 2 x 3
3 adding 2 times also 6 i.e. 3 x 2
So 2 x 3 = 3 x 2

Ex 2:
5 x 2 = ?
5 adding 2 times i.e. 5 + 5 = 10
2 adding 5 times i.e. 2 + 2 + 2 + 2 + 2 = 10

Just watch this table song which explains this.

So many tricks are available for multiplication. Basic requirements to do multiplication is memorizing tables. If  you are good at tables, you will be quicker in calculations. How many tables? at least 10 tables. You can memorize from 6 x 6 to 10 x 10 by using your hand.

To know about the trick watch following video.

Stay tuned for more multiplication tricks. Any queries contact me.

Arithmetic tricks or Maths tricks - 2

In this post we try add decimal numbers.

Practice two digit addition. Even decimals also you can try using two digit addition. For example

Example 1  :  1.26 + 8.23 + 7.26 + 1.45

Its very simple one and just like addition.

But what about following one

Example 2 : 1.2 + 2.34 + 1.234 + 5.6784 = ?

Here confusion arises because number of digits after decimal.

In decimal addition  you need to make number digits should be same for all the numbers. After decimal, max four digits are there. So you make all numbers should have 4 digits after decimal.

1.2000 + 2.3400 + 1.2340 + 5.6784

Now this is similar to  Example 1.

Your calculation will become easy, if you think as centimeter or millimeter etc

As you know 1 meter = 100 centi meter
                     1 meter = 1000 milli meter

Example 3 : 1.23 + 1.2 + 1.234

After decimal, 3 digits are there. So you think after decimal value think it as milli meter. So above numbers as 1 m 230 mm + 1m 200mm + 1m 234 mm

By thinking like this enables you for mental calculation of decimals.

If you have any questions, send mail to fresher.adviser@gmail.com

I am glad to respond to your queries.

Job creator or Job seeker

Before moving into the tips and tricks in written test, let me ask you question.

Why don't you become job creator instead of job seeker?

I know its not as easy as this question. But if you succeed, you have so many advantages as job creator.You can live on your own terms. No need to bother about your credentials or gradings. what matters is do you have knowledge or idea to make it big. Just think about it. Job creation is a pride and honor. No idea what to do and how to do, I am there to guide you. 

you can send mail to fresher.adviser@gmail.com

As a fresher, you have more flexibility to become job creator. No responsibilities, No worries. Only worry is to settle in life. Decide your path as job seeker or job creator. Its matter of time and smart work make you succeed. Dont bother about investment and infrastructure. Venture capitalists are waiting for you invest in your idea, if you can make your idea big. I wish to see everyone as job holder or job creator. 

A problem is an opportunity to become job creator and working on solution is first step towards job creation.

Stay tuned... In next post, you come to know about tips and tricks in Arithmetic