Reporting part-time earnings while on benefits - any advice?

I picked up part-time shifts as a teaching assistant and I am confused about how to report them. Pay posts on a different day from when I work.

I estimated and then checked my pay stub. When there was a small difference I wrote to the agency to correct it.

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.