mental maths

Hi everybody let us see this week how the number 9 can be multiplied with numbers from 11 upto 99. Let me start with the example 42 X 9 = ? Please don’t use the calculator because your brain itself a calculator!!!. Just follow the steps below to multiply the numbers.

42 X 9

(4+1) – 42 X (9+1)


42 – 5 X (10-2)

378

that’s it the answer is 378 now pls check with calculator .

Hi Everybody hope you are visiting to this page regularly now for this week let us listen to Multiply the numbers in more simple ways with mental maths.

Let me start with the Base numbers and complement numbers . The base numbers are denoted as 10, 100, 1000, 10000 etc., and the complement numbers are the difference between the base numbers and the actual numbers for eg., the base number for this digit 4 is 10 and the complement number for this digit is 6 ie., (10 -4 = 6).

Please keep the above said paragraph in your mind always and just follow me.

Let us multiply 8 X 9

The base number for 8 is 10 so (8 – 10 = -2 )
The base number for 9 is 10 so (9-10) = -1)

Now write the number like this


8 -2
9 -1

72

Multiply first (-2 X -1 = 2) this is final number in the answer
Then subtract any one number on diagonal wise (8-1 = 7) or (9-2=7)
Now we got the answer. Ok here is the another example

Let us try 98 X 97 (can u multiply in 6 second ohh yes !!!)


98 -02

97 -03

-----------
98-3 06

answer 9506 check with the calculator now and make sure the answer is correct

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Maths : we are going to discuss the multiplication in maths most of them will be using calculator even for small mulitplication. I think you have landed what you are wondering for ? Welcome to Maths tricks. Here you can learn mental maths very easily. Let us go to the session.

Last session we had seen how to work with the digit 5. Now let us see how to with these types(22 X 28 ; 31 X 39) look carefully the last two digit in the second line is different but same number is in the first line now the sum of second line is 10 if you find any multiplication like this you can apply the same rule as in the previous session.

first multiply the numbers in the second line ie 2 X 8 = 16 then increment one of the first line digit ie 2+1=3 now multiply 3 X 2 =6 the answer for above said is 616 verify it with your calculator.

see the second example is 31 X 39

the sum of second line is 10 first multiply the numbers in the second line ie1 X 9 = 09 then increment one of the first line digit ie 3+1=4 now multiply 4 X 3 = 12 the answer for 1209 verify with your calculator.

Now try this by your own
12 X 18 ; 13 X 17 ; 14 X 16 ; 24 X 26 ; 21 X 29 ; 101 X 109 ; 87 X 83
see soon with next update.