What is the value of a deci unit in decimal form?

A deci unit represents one-tenth of a whole unit in the decimal system. In decimal form, this is expressed as 0.1. This is why the correct answer is the value of a deci unit being 0.1. The concept of metric prefixes is integral to understanding measurements in pharmacology and science in general. The prefix 'deci-' comes from the Latin word "decimus," meaning "tenth," indicating that for any measurement unit labeled with the deci prefix, it is scaled down to one-tenth of that unit. This clear establishment of scale is crucial when calculating doses or concentrations in pharmacological contexts.