How many men did Nebuchadnezzar see walking around in the fiery furnace?

Answer: Four

Three men were thrown in bound, but the king saw four men walking unbound and unharmed, the fourth looking like a son of the gods.

“Suddenly King Nebuchadnezzar jumped up in amazement and asked his advisers, “Did we not throw three men, firmly bound, into the fire?” “Certainly, O king,” they replied. “Look!” he exclaimed. “I see four men, unbound and unharmed, walking around in the fire—and the fourth looks like a son of the gods!””— Daniel 3:24-25 (BSB)