A symbol, usually a letter, which is used to represent one or more numbers.
An expression consisting of numbers and operations.
An expression consisting of at least one variable and also consist of numbers and operations.
A number, a variable, or a product and a number and variable.
The number part of a term that includes a variable. For example, 3 is the coefficient of the term 3x.
A quantity having a fixed value that does not change or vary, such as a number. For example, 5 is the constant of x + 5.
A mathematical sentence formed by setting two expressions equal.
A mathematical sentence formed by placing inequality symbol between two expressions.