The US lives in a metric gray area. It has a few laws requiring that consumer goods list both metric and US customary measures, but it still remains isolated in its US customary measures bubble ...

understand both metric and customary systems of measurement; understand relationships among units and convert from one unit to another within the same system; understand, select, and use units of ...

The United States and United Kingdom shared a system of measurements until 1824, when the Weights and Measures Act standardized the existing British customary units, changing them slightly, and ...