expressions Vocabulary
JamWise Education Team·Updated March 2026
The expressions strand is a core part of the K-8 math curriculum. It encompasses 42 vocabulary terms that students encounter as they progress from kindergarten through 8th grade. Each term builds on previous knowledge, creating a spiral of deepening understanding that prepares learners for increasingly complex concepts.
Understanding expressions vocabulary is essential for classroom discussions, assessments, and real-world application. Below you will find every term organized by grade level, so teachers and parents can quickly identify which words are appropriate for their students and explore definitions tailored to each developmental stage.
6th Grade
(19 terms)
Coefficient
The number that multiplies a variable in an expression. In 7x, the coefficient is 7.
Cubed
Raised to the third power. 4 cubed means 4 × 4 × 4 = 64. It is written as 4³ and represents the volume of a cube with edge length 4.
Dependent variable
The variable whose value depends on another variable. In the equation y = 3x, the value of y depends on what x is.
Distributive property
A rule that says multiplying a number by a sum is the same as multiplying by each addend and then adding. a(b + c) = ab + ac.
Equation
A math sentence that uses an equal sign to show that two expressions have the same value. For example, 3x + 5 = 11.
Equivalent expressions
Two expressions that have the same value no matter what number you substitute for the variable. For example, 2(x + 3) and 2x + 6 are equivalent.
Evaluate
To find the value of an expression by replacing each variable with a given number. To evaluate 3x + 2 when x = 4, substitute 4 for x to get 14.
Exponent
A number that tells how many times the base is used as a factor. In 5 cubed (5³), the exponent is 3, meaning 5 × 5 × 5.
Expression
A combination of numbers, variables, and operations like addition or multiplication. For example, 3x + 5 is an expression.
Formula
An equation that shows the relationship between different variables. A = l × w is a formula for the area of a rectangle.
Independent variable
The variable you can freely choose a value for. In y = 3x, you pick x and then calculate y.
Inequality
A math sentence that compares two expressions using symbols like <, >, ≤, or ≥ to show they are not always equal.
Inverse operations
Operations that undo each other. Addition and subtraction are inverse operations. Multiplication and division are inverse operations.
Order of operations
The rules for the sequence in which to evaluate an expression: parentheses first, then exponents, then multiplication and division left to right, then addition and subtraction left to right.
Solution to an equation
A number that makes an equation true when you substitute it for the variable. The solution to x + 4 = 10 is x = 6.
Solution to an inequality
Any value that makes an inequality true. The inequality x > 3 has infinitely many solutions, including 4, 5, 3.5, and 100.
Squared
Raised to the second power. 5 squared means 5 × 5 = 25. It is written as 5² and represents the area of a square with side length 5.
Term
A part of an expression that is separated by plus or minus signs. In 4x + 3y - 7, there are three terms: 4x, 3y, and 7.
Variable
A letter that represents a number whose value can change. In the expression 3x + 5, the letter x is a variable.
7th Grade
(12 terms)
Constant
A value that does not change. In the expression 4x + 7, the number 7 is a constant because it stays the same no matter what x is.
Distributive property
A property that lets you multiply a sum by distributing the multiplier to each addend: a(b + c) = ab + ac. Works with subtraction too.
Equivalent expressions
Expressions that have the same value for every possible value of the variable. You can show they are equivalent by using properties of operations.
Expand
To rewrite an expression by using the distributive property to remove parentheses. Expanding 3(x + 4) gives 3x + 12.
Factor an expression
To rewrite an expression as a product of its factors. Factoring 6x + 12 gives 6(x + 2).
Inequality
A mathematical sentence comparing two expressions using <, >, ≤, or ≥. The solution is often a range of values shown on a number line.
Like terms
Terms that have the same variable raised to the same power. You can combine like terms: 3x + 5x = 8x.
Linear expression
An expression with a variable raised only to the first power. For example, 3x + 7 is linear, but 3x² + 7 is not.
Opposite operations
Operations that undo each other when solving equations. Addition undoes subtraction; multiplication undoes division.
Two-step equation
An equation that takes two operations to solve. For example, 2x + 3 = 11 requires subtracting 3 and then dividing by 2.
Two-step inequality
An inequality that takes two inverse operations to solve. For example, 3x - 5 > 7 requires adding 5, then dividing by 3.
Variable
A letter or symbol that represents an unknown quantity in an expression or equation. The variable can take on different values.
8th Grade
(21 terms)Coefficient
A constant that a variable or expression is multiplied by. In 8x, the coefficient is 8. If no number is written, the coefficient is 1.
Constant
A fixed value that does not change. In the expression 5x + 3, the number 3 is a constant.
Elimination
A method for solving a system of equations by adding or subtracting the equations to eliminate one variable.
Equation
A mathematical statement that two expressions are equal, connected by an equals sign. For example, 2x - 5 = 11.
Exponent
The number written as a superscript that tells how many times the base is multiplied by itself. In 3⁴, the exponent 4 means 3 × 3 × 3 × 3.
Expression
A combination of numbers, variables, and operations. Unlike an equation, an expression does not have an equals sign.
Laws of exponents
Rules for working with exponents: when multiplying same bases, add exponents (aᵐ × aⁿ = aᵐ⁺ⁿ); when dividing, subtract exponents; when raising a power to a power, multiply exponents.
Like terms
Terms that have the same variable raised to the same power. 3x and 7x are like terms; 3x and 3x² are not.
Linear equation
An equation whose graph is a straight line. It can be written in the form y = mx + b, where m and b are constants.
Negative exponent
An exponent that means you take the reciprocal. For example, 2⁻³ = 1/2³ = 1/8. Moving from the numerator to the denominator changes the sign.
Point-slope form
A way to write a linear equation when you know the slope and one point. Written as y - y₁ = m(x - x₁).
Power
An expression written as a base raised to an exponent, like 2⁵. The base is 2 and the exponent is 5, meaning 2 × 2 × 2 × 2 × 2.
Scientific notation
A way to write very large or very small numbers as a number between 1 and 10 multiplied by a power of 10. For example, 93,000,000 = 9.3 × 10⁷.
Slope
A number that measures how steep a line is. Slope equals the rise (vertical change) divided by the run (horizontal change) between any two points on the line.
Slope-intercept form
The form y = mx + b for a linear equation, where m is the slope and b is the y-intercept.
Solution of a system
An ordered pair that satisfies every equation in the system. Graphically, it is the point where the lines intersect.
Standard form of a linear equation
A linear equation written as Ax + By = C, where A, B, and C are constants and A and B are not both zero.
Substitution
A method for solving a system of equations by replacing a variable in one equation with an expression from the other equation.
System of equations
Two or more equations that are solved together. The solution is the point (or points) that makes all equations true at the same time.
Y-intercept
The point where a line crosses the y-axis. In the equation y = mx + b, the y-intercept is the value b, which is the point (0, b).
Zero exponent
Any nonzero number raised to the power of 0 equals 1. For example, 5⁰ = 1 and 100⁰ = 1.