How to interpret scientific notation? I'm having a problem understanding scientific notation. What is the difference between the following:

$$\text{5e2, 5e-2, -5e2, -5e-2}$$
\begin{align}
5e2 &amp; = 5\times 10^2 = 500 \\
5e{-2} &amp; = 5\times 10^{-2} = 0.05 \\
-5e2 &amp; = -5\times 10^2 = -500 \\
-5e{-2} &amp;  = -5 \times 10^{-2} = -0.05
\end{align}
This image should help hopefully.