How to be a less shit entry level employee

"Where is the rebate in these numbers?" There was silence on the conference call as I filled up with dread. I had made a hundred thousand dollar mistake and circulated it to all of the directors. I simply missed it. There was no other reason. Luckily it was for a prospective purchase, so I hadn't actually lost a hundred thousand dollars (yet), but that was little comfort to me as the directors waited for my response. "Fuck, it's not there, I made a mistake."