Here is the situation...

We have some (4-5 holes from 1" to 4" in diameter) holes that have been
knocked into the wall of some baseball dugouts.

The 1" holes are no problem but the bigger holes are. What is the best way
to fill the cavities so that we can patch the holes with cement - ultimately
going to paint the walls?

Any suggestion for quick, easy and cheap repair?

Structural integrity not an issue.

Cost is a major factor as this is a middle school field with zero funding.
I'll probably end up doing this out of my own pocket.