Old Bones

From Emazing.Com's Fun And Games Newsletter

One day at the Chicago Museum of Natural History, a group of tourists were marveling over the dinosaur bones. One of them turned to the nearby guard and asked, "Can you tell me how old these dinosaur bones are?"

"Those bones there are three million, four years, and six months old." The guard replied.

"Wow!" the tourist exclaimed. "How do you know their age so precisely?"

The guard answered, "Well, the dinosaur bones were three million years old when I started working here, and that was four and half years ago."