    Sentence 1: If [math] \frac{1}{1} =1,  \frac{2}H2} = 1, \frac {5}{5} = 1...  {/math] why [math] \frac{O}{0}  \neq 1 [/math]?    Sentence 2: Division by Zero: If  1/1 equals 1, 2/2 equals 1, and 5/3  equals 1, then what does 0/0  equal?