Input (grade 7): The classical period of Ancient Greece corresponds to most of the 5th and 4th centuries BCE (i.e. from the fall of the Athenian tyranny in 510 BC to the death of Alexander the Great in 323 BC).
Output (grade 10): The classical period of Ancient Greece was from the fall of the Athenian tyranny in 510 BC to the death of Alexander the Great in 323 BC).