Context: In 1840, St Helena became a provisioning station for the British West Africa Squadron, preventing slavery to Brazil (mainly), and many thousands of slaves were freed on the island. These were all African, and about 500 stayed while the rest were sent on to the West Indies and Cape Town, and eventually to Sierra Leone.

Question: In 1840 what did Saint Helena become?
Answer: a provisioning station

Question: What squadron was Saint Helena a provisioning station for?
Answer: British West Africa Squadron

Question: What country did the British West Africa Squadron prevent slaves from being sent to?
Answer: Brazil

Question: How many slaves ended up staying on the island after being freed?
Answer: 500

Question: How many slaves were freed from the island?
Answer: many thousands