Which of these five numbers is the largest?
$\text{(A)}\ 13579+\frac{1}{2468} \qquad \text{(B)}\ 13579-\frac{1}{2468} \qquad \text{(C)}\ 13579\times \frac{1}{2468}$
$\text{(D)}\ 13579\div \frac{1}{2468} \qquad \text{(E)}\ 13579.2468$
The options given in choices $\text{A}$, $\text{B}$ and $\text{E}$ don't change the initial value (13579) much, the option in choice $\text{C}$ decreases 13579 by a lot, and the one given in choice $\text{D}$ increases 13579 by a lot.  
After ensuring that no trivial error was made, we have $\boxed{\text{D}}$ as the answer.