Original sentence: At the Battle of Thermopylae, a small force of about 7,000 Greeks, most of which surrendered, led by King Leonidas of Sparta held off a large Persian army that numbered around 200,000
Edited sentence: At the Battle of Thermopylae, a small force of about 7,000 Greeks, most of which surrendered, led by King Leonidas of Sparta held off a large Persian army that numbered around 500,000