Math is Fun!

Calculator Fun 2

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  • Think of a three digit number
  • Multiply it successively by 7, 11 and 13
  • What is the result?

For example, if your three digit number is 168

     168 x 7  = 1176
    1176 x 11 = 12936
   12936 x 13 = 168168

It is the original three digit number repeated twice!

Why it works

Since 7 x 11 x 13 = 1001, then any three digit number abc x 1001 = abcabc

      abc		   349
   x 1001		x 1001
      abc		   349
       0		    0
      0			   0
   abc   		349   
   abcabc 		349349

It is math Made Simple and Cool!

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Calculator Fun 1

by | Math is Fun! | No Comments

1) Think of a two digit number
2) Multiply it successively by 3, 7, 13, and 37
3) What is the result?

For example you r two digit number is 97.

   97 x 3  = 291
  291 x 7  = 2037
 2037 x 13 = 26481
26481 x 37 = 979797

It is the same two digit number repeated three times!

Why does it work?

Since 3 x 7 x 13 x 37 = 10101, then any two digit number ab x 10101 = ababab

           ab	           59
      x 10101	      x 10101
           ab	           59
           0	           0
         ab  	         59
         0	         0
       ab    	       59    
       ababab          595959

That is Math, Simple and Cool!

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