Avoirdupois facts for kids

The avoirdupois system is a way to measure how heavy things are. It's built around a unit called the pound, which is made up of 16 ounces. This system is used for everyday measurements in the United States. You'll also find it still used by many people in Canada, the United Kingdom, and Ireland.

What is the Avoirdupois System?

The avoirdupois system helps us measure the weight or mass of objects. Imagine you're buying groceries; the weight of your apples or a bag of flour is often measured using this system. It's one of the oldest ways people have measured things.

How Avoirdupois Measures Weight

The main unit in the avoirdupois system is the pound.

• One pound is equal to 16 ounces. Think of it like this: if you cut a cake into 16 equal slices, each slice could represent an ounce, and the whole cake would be a pound.
• A pound also equals 7,000 smaller units called grains. Grains are very tiny units of weight, often used for very precise measurements, like for medicines or precious metals.
• In terms of the metric system, one avoirdupois pound is about 453.59 grams.

Where Avoirdupois is Used Today

Even though most of the world uses the metric system (with kilograms and grams), the avoirdupois system is still very common in certain places.

• The United States uses avoirdupois for almost all its everyday measurements, from food to body weight.
• In Canada, the United Kingdom, and Ireland, you'll find a mix. While they officially use the metric system, many people still use pounds and ounces, especially for things like body weight or buying certain foods.

A Brief History of Avoirdupois

The avoirdupois system has a long and interesting history. It first became popular in Europe during the High Middle Ages, around the 12th century.

• It was especially important for wool traders in the Kingdom of England and the Low Countries (which are now places like Belgium and the Netherlands). Wool was a very valuable product, and traders needed a reliable way to measure it accurately.
• As more people moved to towns and cities, and a new middle class grew, the need for standard measurements became even more important for trade and business. The avoirdupois system helped make sure everyone was using the same measurements.

Images for kids

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  Finely crafted pan balance or scales with boxed set of standardized gram weights sequenced in units of mass. Such scales are used to make the most accurate of fine measurements, such as in the needs of empirical chemistry.

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  Robust weights like these hexagonal decimal-scaled antiques were used for trade into the late 20th century.

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  The units first became used by wool traders in the Kingdom of England and the Low Countries during the end of the High Middle Ages, as population growth and the Renaissance gave rise to an increasingly numerous town population and a newly established middle class.

See also

In Spanish: Avoirdupois para niños