The Beauty of Mathematics

   1 x 8 + 1 = 9
   12 x 8 + 2 = 98
   123 x 8 + 3 = 987
   1234 x 8 + 4 = 9876
   12345 x 8 + 5 = 98765
   123456 x 8 + 6 = 987654
   1234567 x 8 + 7 = 9876543
   12345678 x 8 + 8 = 98765432
   123456789 x 8 + 9 = 987654321
 
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   1 x 9 + 2 = 11
   12 x 9 + 3 = 111
   123 x 9 + 4 = 1111
   1234 x 9 + 5 = 11111
   12345 x 9 + 6 = 111111
   123456 x 9 + 7 = 1111111
   1234567 x 9 + 8 = 11111111
   12345678 x 9 + 9 = 111111111
   123456789 x 9 +10= 1111111111
 
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   9 x 9 + 7 = 88
   98 x 9 + 6 = 888
   987 x 9 + 5 = 8888
   9876 x 9 + 4 = 88888
   98765 x 9 + 3 = 888888
   987654 x 9 + 2 = 8888888
   9876543 x 9 + 1 = 88888888
   98765432 x 9 + 0 = 888888888
  
 Brilliant, isn't it?

   And finally, take a look at this symmetry:

   1 x 1 = 1
   11 x 11 = 121
   111 x 111 = 12321
   1111 x 1111 = 1234321
   11111 x 11111 = 123454321
   111111 x 111111 = 12345654321
   1111111 x 1111111 = 1234567654321
   11111111 x 11111111 = 123456787654321
   111111111 x 111111111 = 12345678987654321