This question points out the danger of thinking in words, rather than thinking in pictures and ideas. If you just think in words you might reason: “To float, the battleship must displace its own weight in water. Its own weight is 100 tons, but there is only 100 pounds of water available — so it cannot float.” But if you picture the idea you will see the displacement refers to the water that would fill the ship’s hull if the inside of the ship’s hull were filled to the water-line. And this displacement is 100 tons.
Don’t rely on words, or equations, until you can picture the idea they represent.
