Final answer:
Xerxes lost around 6,400 soldiers at Thermopylae, but the exact number is uncertain. The Battle of Thermopylae delayed the Persians and gave the Athenians time to defeat the Persian navy.
Step-by-step explanation:
The total number of troops that Xerxes lost at Thermopylae is not known with certainty, but it is estimated that the Persians lost around 6,400 soldiers, while the Greeks lost 192 soldiers. Some Greek sources claim that the number of Persians lost was even higher, possibly as many as 60 Persians per Athenian. Despite the defeat, the Battle of Thermopylae was a significant delay tactic that allowed the Athenians enough time to position their navy and ultimately crushed the Persian navy in a single day.