12.2.31 Number theory

Problem: Let \( n=\overline{a_{h} a_{h-1} \ldots a_{0}} \) be a positive integer. Prove that \( n \) is divided by \( 2^{k} \) or \( 5^{k}(k \leq h) \) only when the number \( \overline{a_{k-1} \ldots a_{0}} \) is divided by it.