Mathematic Interesting Facts

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These are very interesting fact that you might never think of before.

Do you know;

1. Letters 'a', 'b', 'c' &'d' do not appear anywhere in the spellings of 1 to 99
   ( Letter 'd' comes for the first time in Hundred )
   
   
2. Letters 'a', 'b' & 'c' do not appear anywhere in the spellings of 1 to 999
   ( Letter 'a' comes for the first time in Thousand )
   
   
3. Letters 'b' & 'c' do not appear anywhere in the spellings of 1 to 999,999,999
   ( Letter 'b' comes for the first time in Billion )
   
   
4. Letter 'c' does not appear anywhere in the spellings of entire English counting

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