You are assigned to optimize a Python application performing extensive calculations. Which approach would you take to reduce the computational time and improve the efficiency of the calculations?

To reduce computational time and improve efficiency in a Python application with extensive calculations, you should use parallel processing. This involves splitting the calculations into multiple threads or processes to utilize multi-core CPUs. Increasing screen resolution and adding more memory won't directly impact computational efficiency. Switching to a different programming language may not be necessary and can introduce development challenges.