A long ton is a way of measuring how heavy something is. It's like when you ask, "How heavy is that bag of flour?" and someone might say, "It weighs two pounds." But long tons are bigger than pounds.
A long ton is equal to 2,240 pounds. That's like putting 22 grown-up people on a scale and seeing how much they weigh all together!
Long tons are mostly used in places like the United Kingdom or Australia, where they have different measurement systems than we do in the United States. So if someone says something weighs 3 long tons, that means it's as heavy as 6 elephants all standing on the same scale! That's a LOT of weight!
But don't worry, you don't need to use long tons in your everyday life unless you live in a place where it's used more often. For most things, we use pounds or kilograms to measure weight.