Trick to multiply any digit number by any digit number in seconds

Hey Friends

Hope my Tricks are useful to you all. You should practice them so as to get used to with it. once they are on your mind it won't take more than 3 seconds to solve questions in the exam.
And I must tell you all your time will run at speed of the rocket in the examination.

So let me tell you the trick

  • Take any  Two digit number say 43 and it is to be multiplied by 13


43 *13=?

now,
 step 1:  reverse the number with which we have to multiply that is  13 over here.
             
                   so reverse of 13 is 31

step 2: here write 31 under 43 such that 1 of 31 comes under 4 of 43 and than multiply 4*1=4 so consider for now 4 as initial digit of final answer.

                                           ANS:- 4__ __
\
step 3  :now here shift 31 one place to right such that 31 comes under 43 and than multiply (4*3) and add it with (3*1) which gives 15 now here of 15 is carried forward to 4 which is initial digit of FINAL answer so now initial digit of final answer is 5and second digit is also 5 .                                                                                   ANS:-  55___
step 4 now shift the multiplier that is 31 in this case uptil the first digit of multiplier comes underneath the last digit of multiplicand that is 43 here .And repeat the process as above every time . now here we multiply (3*3) and we get 9 that is final digit of answer. 
                                                         ANS:- 559

                                                     The Final Answer is 559

  • Similarly take any 3 digit number and multiply it by any two digit number 


Say , 152 *45 step 1:reverse 45 ,so 54 
    So take 152 and 54= (1*4)    (1*5+5*4)     (5*5+2*4)    (2*5)  
                                =4   (5+20)    (25+8)     (10)                                  =4(2   5)(3    3)(1   0)(the one in red are to be added)                                      +       +         +                                  = 6        8        4     0

                                  Thus Final answer   152*45=6840

         Take any three-digit number and multiply it by another 3 digit number.

Lets  take 123 and 456 ,so 123*456  step 1:reverse 456 so 654.step 2: Write 654 below 123 in such a way that 4 comes under 1 of 123                                  1      2        3                6     5       4
do same steps as above  thus,123*456=  (1*4) (1*5+2*4)   (1*6+3*4+2*5)  (2*6+3*5)   (6*3)                =4 (1   3) (2   8) (2    7) (1  8)                    +        +         +        +               =55(10)88                    +123*456=56088
                                  Thus the Final answer  is 123*456=56088


  • similarly for any digit multiplicand (the number which is to be multiplied) and digit multiplier (number which multiplies )  trick is same.






Let's take few examples.

First, try it and then check the solution and answer given.
Try to do it orally so as to save time in the exam.

1.  79*51=?
2.  123*16=?
3.  3894*52=?
4.  89723*34=?
5.  4544*1234=?

Solution.

1   79*51=4029
   
     method: reverse :15,  (7*5)   (7*1+9*5)    (9*1) =>(35) (52) (9)=>(3 (5+5)) 29=>(3+1)029=>4029


2.    123*16=1968
  
          method: reverse:61,      1   8     15     18=>  1(8+1)(5+1)8=>1968

3.  3894*52= 202488

          method: reverse:25 ,    15   46   61  38 8  =>1(5+4)(6+6)(1+3)88=>1 9 12  4 8 8=> 
1(9+1)2488=>(1+1)02488=>202488

4.   89723*34=3050582
   
        method:reverse:43,       24 59 57 34 17 12=>2(4+5)(9+5)(7+3)(4+1)(7+1)2=> 
29(14)(10)582=>2(9+1)(4+1)0582=>(2+1)050582=>3050582
5  4544*1234=5607296

              method: reverse 4321,          4    13    26   43     40   28   16=>(4+1)(3+2)(6+4)(3+4)(0+2)(8+1)6=>55(10)7296=>5(5+1)07296=>5607296
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