Problem is, all of the age-of-earth figures we've seen since childhood are based on certain kinds of assumptions, most if not all of which are invalidated if one allows for the possibility of a worldwide flood in the last 10,000 years.
Noah's Flood magically creates the fossil record, conveniently putting more primative forms of life at the bottom, and more advanced types nearer to the surface.
It also sorted them nicely so that no humans or their tools they might have used to build the ark are found anywhere near the fossils the Flood created.