ABSTRACT
Scientists need to make quantitative statements about the physical quantities measured in their experiments. Algebra provides the language and grammar to make these statements. There are various systems for choosing units and conventions for how physical quantities are to be described. Algebra is the basic language for stating many of the fundamental relationships between the real physical quantities that we describe. The symbols for physical quantities are combined in physical value equations to make statements about the real world. This use of physical value equations is almost universal among scientists so it is vitally important to understand the distinction between a number and a physical quantity. A physical value equation states a relation between physical quantities. When using the equation for calculations each variable standing for a quantity must take on a numerical value and its associated unit.
