Quantities in Formever are always an amount of some Unit or Currency or Rate. Units can be dimensional or dimensionless. Dimensional units such as weight include kilograms, pounds, grams, ounces and many other weights that come from different parts of the world.
Other dimensional units are length, area, volume, energy, currency, duration. Formever enforces correct dimensionality. For example you cannot multiply currency by currency as the result makes no sense from a dimensional point of view. You can multiply hours by currency/hour as the result is a currency amount. Dimensionless quantities can multiply and divide any quantity. You can add two quantities of the same dimensionality together but not two quantities of differing dimensionalities.