I agree that LLM output need to be validated to be valuable but math (unless it's on a quite high level I suppose) seems like one of the areas with the most potential for doing validations, without requiring an expert to validate everything.

If you're working on educational math problems with solutions you can validate against the solutions. If you're working with proofs you can evaluate the proofs in a proof checker. Or you can run the resulting math expressions through a calculator.