A gram, or gramme, is a unit of measure in the metric system. It measures mass, or how much matter something is. The symbol is g. One gram used to be defined as the mass of one cubic centimetre of pure water at 3.98 degrees Celsius. Now one gram is defined as 1/1000 of a kilogram. A milligram is 1/1000 of a gram.
- "Metric system - Facts from the Encyclopedia". Yahoo! Education. Retrieved 3 June 2013.