A solution with pH=2 is more acidic than one with a pH=6 , by a...

\begin{aligned} & \text{ } \mathrm{pH}=-\log \left[\mathrm{H}^{+}\right] \\ & \Rightarrow \mathrm{pH}=2 \Rightarrow\left[\mathrm{H}^{+}\right] \text{for } \mathrm{pH}=2 \text{ is } 10^{-2} \\ & \mathrm{pH}=6 \Rightarrow\left[\mathrm{H}^{+}\right] \text{for } \mathrm{pH}=6 \text{ is } 10^{-6} \\ & \Rightarrow \quad \frac{10^{-2}}{10^{-6}}=10^4=10,000 \\ & \end{aligned}