Since $3 = \frac{6}{2}$ and $\frac{5}{2} < \frac{6}{2}$, then $\frac{5}{2} < 3$. Since $3 = \sqrt{9}$ and $\sqrt{9} < \sqrt{10}$, then $3 < \sqrt{10}$. Thus, $\frac{5}{2} < 3 < \sqrt{10}$, and so the list of the three numbers in order from smallest to largest is $\frac{5}{2}, 3, \sqrt{10}$.