I am preparing a Beamer slide with two simple equations. I wanna include this in a block as shown below.

```
\begin{block}{Equation}
\begin{align*}
r &= a + b \\
s &= c + d
\end{align*}
\end{block}
```

It looks alright, the only problem is that it wastes so much space above and below the equations. I tried vspace{-2cm} but it did not have any effect. Any other idea how I could reduce the empty area above and below the equations. Might it be possible that the block size is fixed and thats the problem why it takes so much space?

Many thanks for your help