Multiplication of numbers who units digits sum is 10

 Hi, Here I come up with one more trick in multiplication which is multiplication of 

Numbers ending with digits whose sum is 10 and Have same ten's digits

 As usual let's take two number easy numbers which are 

12 x 18=?

Are you taking some time are taking some paper to multiply, You would not in need of these things if you read this page once, I say the answer is 216.  How? below is the answer for this How.

Step 1: Identify the basic

We have ten's digits same which is 1

So, we are going to see what is the next number of 1, Yes, it is true 2 is the next number of 1

Step 2: Proceed Further

Multiply the two number which we found in the previous step Which are 1 and 2

so, 1 x 2 =2

This will be our first digit in our result you can observe.

Step 3: Go for the main observations

Now, observe the units digits which are 2 and 8 in this case You also observe that these two numbers sum is 10 (2+8=10) correct right.

NOTE: This is necessary condition for this trick ( tens digits sum should be 10)

Step 4: Multiplication of numbers

 Now multiply the ten's digits 2 x 8=16

This becomes our second part of the answer. Observe please

Step 5: Placing all in place

Now the result obtained in the Step 2 and Step 4 join together we get our answer as 216

It is as simple as it is said.

so the answer for 12 x 18 is 216

End of process

Now, check out this trick with other numbers as well 

See the below video made by kids to see few more examples and kinds in it

To watch Video click me

Now let's check this trick with some other three digit numbers as well

Here we go, 

First to apply the trick we have to check whether the units digits sum is 10 or not, above picture shows it is.

This picture is evident to say that we can apply the trick.

Step 1 is applied here so here we go multiplying the units digits 7 x3=21,

The result obtained in the step one serves as the last part of our required answer so see the above and below pictures to connect with the words.

Now time to go for the further steps Which is multiplication of the ten's and hundred's digits 

Here we are using the technique which we have already seen in the last blog which is multiplication of numbers ending with 1. Which goes like this we have 21, 21 in the 10's and 100's digits respectively.

On multiplying 21 x 21=441 by using trick (2x2)(2+2)1.

This serves as the one more part of our answer which as shown in the above picture.

 

Hope you have understood it, 

If you still have a doubt in it follow the gif below

If your doubt still persists please ask me in the comments section.

have a good day... :-)

Knowledge stops where Learning stops

so,  Keep learning.