So don't be intimidated when your children bring home schoolbooks talking about millions of years. Just turn to the section dealing with fossils and show them that fossils have to be formed quickly. That one simple fact contradicts the vast ages ascribed to large segments of the geological record. Of course, the age of the earth is not as important for creation as it is for evolution. The important thing is that God created the world, not when He created it.
Christians can be open-minded about the question of age, and follow the evidence wherever it leads.
But evolution absolutely requires an ancient earth. Evolution pictures a world where tiny changes add up gradually, as one-celled organisms slowly evolve into fish and fowl and guinea pigs. There are enough puzzles in the rocks to make us doubt it. Mother Nature is too shy to tell her age outright. But the clues she does give suggest she's much younger than the millions of years we read about in our science textbooks.