VariableA letter that stands for a number. Here x and y.
CoefficientThe number that multiplies the variable. In 3x it is 3.
ConstantA number on its own, with no variable attached. Here 5, 20 and 7.
OperatorThe sign that tells you what to do. Plus means add, minus means subtract.
Equals signIt says the two sides have the same value.
ExponentThe small raised number. It shows how many times x is used as a factor.
Bracketed parts 4
TermOne piece of an expression, here 3x. Plus and minus signs split the terms.
Left sideEverything to the left of the equals sign. Here it is 3x + 5.
Right sideEverything to the right of the equals sign. Here it is 20.
ExpressionNumbers, letters and operators with no equals sign. Each side of an equation is one.
How this list was compiled: Every name was read on 2026-10-01 in at least two of these. (1) Wikipedia, English edition: Equation, https://en.wikipedia.org/wiki/Equation (two expressions joined by an equals sign; the left-hand side and the right-hand side; terms; variables); Algebraic expression, https://en.wikipedia.org/wiki/Algebraic_expression (its terminology figure: exponent, coefficient, term, operator, constant, variables); Coefficient, https://en.wikipedia.org/wiki/Coefficient (a constant term, or simply constant, is not attached to a variable). (2) California Department of Education, California Common Core State Standards: Mathematics, https://www.cde.ca.gov/be/st/ss/documents/ccssmathstandardaug2013.pdf, read with pdftotext (grade 6: parts of an expression named as term, factor and coefficient; whole-number exponents; a variable can represent an unknown number; both sides of an equation; the equal sign; a constant term). (3) University Algebra, a textbook of 1892 in the public domain, https://archive.org/details/universityalgebr00vanvrich (a term is each part formed when an expression is broken just before each sign + and -; the coefficient; the exponent as the small figure written above and to the right, showing how many times the number occurs as a factor; an equation as the statement of equality between two expressions; its left and right sides; the sign of equality; a symbol of operation, or simply an operator; constants and variables). The examples are checked: 3 x 5 + 5 = 20, so x = 5 makes the top equation true. Hints, detail lines and the order are our own. Licence: own work
The drawing: Drawn for this site by script, 2026-10-01. Own work. Licence: own work
How it works
Label the parts of an equation on two examples, 3x + 5 = 20 and y = 2x² − 7: the variable, coefficient, constant, operator and term, the equals sign and the two sides, an expression and an exponent.
Read the full guide
The top equation
In 3x + 5 = 20 the letter x is the variable and the 3 in front of it is its coefficient. Together they make the term 3x. The 5 is a constant, joined on by the operator +. The equals sign splits the equation into a left side, 3x + 5, and a right side, 20, which is a constant too.
The bottom equation
In y = 2x² − 7 the small raised 2 is an exponent: x is used twice as a factor. The bracket marks 2x² − 7, an expression. An expression has no equals sign; an equation joins two of them.
A variable with no number in front has a coefficient of 1, which is usually left out: x means 1x.
Questions and answers
What are the parts of an equation?
An equation is two expressions joined by an equals sign. Each expression is made of terms. A term can hold a coefficient, a variable and an exponent, or be a constant. Operators such as + and − join the terms.
What is the difference between an expression and an equation?
An expression has no equals sign: 3x + 5 is one. An equation says two expressions are equal: 3x + 5 = 20. So an equation always has a left side and a right side.
What is a coefficient in math?
The number that multiplies a variable. In 3x the coefficient is 3, and in 2x² it is 2. When no number is written, as in x, the coefficient is 1.
What are the parts of a chemical equation?
Reactants, products, the yields arrow, coefficients and subscripts. Those are on the chemical equation page of this site; this page names the parts of an equation in math.