a. Jim uses his calculator to see if a number n having eight or fewer digits is divisible by a number d. He finds that has a display of 32. Does Ι ? Why?

b. if gives a display of 16.8, does Ι ? Why?

Question

a. Jim uses his calculator to see if a number n having eight or fewer digits is divisible by a number d. He finds that   has a display of 32. Does  Ι ? Why?
   
  b. if   gives a display of 16.8, does  Ι ? Why?

mathmate · Answer

On most calculators, if it gives a whole number as the answer, it is very likely that n is divisible by d.  If we would like to be 100% sure, we multiply d by 32 and see if we get back n.  If we do, then d|n, or d divides n.
If it gives a display of 16.8, then n is not divisible by d.