What is the value you put into a formula or equation

Formula is a statement written with group of mathematical symbols that express a relationship.

Equation is type of mathematical formula with sign equal that separates the left side and the right side of the formula.

The value you put into a formula or equation is referred as a variable. The variable is an item ("thing") which can be measured quantitatively and re presented by a number. Variables are called variables because they vary, i. e. they can have a variety of values. If a variable has only one value, it is called constant.