Factory Worker

A factory worker at a factory that made hammers, screwdrivers and other small tools, was seen taking the trash through the front door in a wheelbarrow.
The security guard stopped him and informed the employee that he would have to examine the trash to be sure there were nothing being smuggled out of the factory.
The employee didn't object and the guard proceeded to searched the trash. He did not find anything unusual and let the employee continue.

The next day, the employee again took the trash out with a wheelbarrow.
As expected, the guard insisted upon searching the trash, but still found nothing unusual.
This continued for a month and the security guard was becoming extremely suspicious.

One day, he decided he would confront the employee. When the employee brought out the trash, the guard said, "I know you are taking something from here but I just can't find it. You had better confess now or else!"

The employee decided there was no way out and he said, "You know all the times I have taken out the trash and you searched it and found nothing?"

"Yes..." replied the guard, eager for an answer.

The employee continued, "Well so far I have taken 30 wheelbarrows."