What is $56.78-43.6?$
We can organize this subtraction more quickly using columns as follows:   \[
\begin{array}{@{}c@{\;}c@{}c@{}c@{}c}
& 5 & 6. & 7 & 8 \\
- & 4 & 3. & 6 &
\\ \cline{1-5}
& 1 & 3. & 1 & 8 \\
\end{array}
\] The answer is $\boxed{13.18}$.