Avoirdupois is a fancy way of saying weight. Imagine you have a big bag of toys, and you want to know how heavy the bag is. You can use something called avoirdupois to measure it.
Avoirdupois works by using pounds, which is a unit of weight. You might use pounds when you weigh yourself on a scale, for example. 1 pound is equal to 16 ounces.
So if you have a big toy bag that weighs 32 pounds, that means it's the same as having 512 ounces of toys because there are 16 ounces in every pound (16 x 32 = 512).
Avoirdupois can come in handy when measuring things that are heavy, like mail or packages. It's also used in some countries, like the United States and Canada, as a standard way to measure weight for things like food and medicine.
So remember, avoirdupois is just a fancy word for weight, and it uses pounds and ounces to measure how heavy things are.