The valence electrons in the metal atom in the lattice structure can delocalize and move freely. The electrons are "loosely" connected with their parent atom in the metallic bond because most metals have excess electrons in their outer orbitals above the stable configuration.
Your answer cannot be MORE precise than the least precise measurement. The following rule applies for multiplication and division: The LEAST number of significant figures in any number of the problem determines the number of significant figures in the answer.
