Middle School Math
Middle school math builds the bridge between arithmetic and algebra. In grades 6 through 8, students master fractions, decimals, and percents; learn about ratios and proportions; explore basic geometry and measurement; and begin working with variables and equations. This page organizes every middle-school-level math term on Mathwords by topic so you can find exactly what you need.
Triangle types, congruence tests, special lines in triangles, and triangle properties
Function notation, domain, range, types of functions, and function operations
Types of angles, angle relationships, parallel lines, transversals, and perpendiculars
Polynomial operations, factoring, synthetic division, and polynomial theorems
Slope, linear equations, systems of equations, and graphing lines
Types of numbers: integers, rationals, reals, primes, composites, and number classification systems
Exponential functions, logarithms, growth/decay, and their properties
Circle properties, arcs, sectors, chords, tangent lines, and inscribed angles
Basic arithmetic operations, exponents, powers, roots, and order of operations
Combinations, permutations, probability rules, and counting principles
2D measurement formulas for area and perimeter of common shapes
Fractions, decimals, mixed numbers, and operations with fractions
Mean, median, mode, standard deviation, variance, and measures of spread
Absolute value definition, equations, inequalities, and rules
3D measurement: surface area and volume of prisms, cylinders, cones, spheres, and other solids
Quadrilaterals, regular polygons, and their properties
Coordinate plane, distance formula, midpoint, analytic geometry, and coordinate systems
Descriptive statistics, data visualization, distributions, and sampling
Ellipses, hyperbolas, circles, and their equations
Probability rules, conditional probability, Bayes theorem, and probability calculations
Linear regression, correlation, least squares, and data relationships
Factors, multiples, GCF, LCM, prime factorization, and divisibility
Direct, inverse, and joint variation; proportional relationships
Core algebra vocabulary, properties, and general mathematical concepts
Measurement, scientific notation, rounding, significant digits, and mathematical notation
Translations, reflections, stretches, compressions, and symmetry of graphs
Sets, set operations, Venn diagrams, and set notation
Regular polyhedra, Euler's formula for polyhedra, and special 3D shapes
Linear regression, correlation, hypothesis testing, and statistical inference
Reflections, rotations, translations, dilations, and isometries in geometry
Foundational geometry concepts, planes, measurement units, non-Euclidean geometry, and general vocabulary
Algebraic properties, number classifications, and equivalence relations
Function analysis, advanced algebra connections, and precalculus methods
Histograms, box plots, scatter plots, and data visualization methods
Interest, annuities, present/future value, and financial formulas
Upper/lower bounds, bounded sets, intervals, and ordering concepts
All Middle School Math Terms A–Z (802)
- AA Similarity
- AAS Congruence
- Abscissa
- Absolute Value
- Absolute Value Equation
- Absolute Value Function
- Absolute Value Rules
- Acceleration
- Accuracy
- Acute Angle
- Acute Triangle
- Addition Rule
- Additive Inverse of a Number
- Additive Property of Equality
- Adjacent
- Adjacent Angles
- Aleph Null
- Algebra
- Algebraic Numbers
- Alternate Angles
- Alternate Exterior Angles
- Alternate Interior Angles
- Altitude
- Altitude of a Cone
- Altitude of a Cylinder
- Altitude of a Parallelogram
- Altitude of a Prism
- Altitude of a Pyramid
- Altitude of a Trapezoid
- Altitude of a Triangle
- Amortization
- Analytic Geometry
- Analytic Methods
- Angle
- Angle Bisector
- Angle of Depression
- Angle of Elevation
- Angle of Inclination of a Line
- Angle Sum Property of a Triangle
- Annuity
- Annulus
- Antipodal Points
- Apex
- Apothem
- Arc of a Circle
- Area of a Circle
- Area of a Convex Polygon
- Area of a Kite
- Area of a Parabolic Segment
- Area of a Parallelogram
- Area of a Rectangle
- Area of a Regular Polygon
- Area of a Rhombus
- Area of a Sector of a Circle
- Area of a Segment of a Circle
- Area of a Trapezoid
- Area of a Triangle
- Area of an Ellipse
- Area of an Equilateral Triangle
- Argument of a Function
- Arithmetic
- Arithmetic Mean
- Arm of an Angle
- ASA Congruence
- Associative
- Asymptote
- Average
- Average Rate of Change
- Axes
- Axis of a Cylinder
- Axis of Reflection
- Axis of Rotation
- Axis of Symmetry
- Back-Substitution
- Bar Graph
- Base
- Base in an Exponential Expression
- Base of a Trapezoid
- Base of a Triangle
- Base of an Isosceles Triangle
- Bayes' Theorem
- Bernoulli Trials
- Between
- Biconditional
- Big O Notation
- Binary / Base 2
- Binomial
- Binomial Coefficients
- Binomial Coefficients in Pascal's Triangle
- Binomial Probability Formula
- Binomial Theorem
- Bisect
- Bisector
- Bivariate Data
- Boolean Logic
- Bounded Function
- Bounded Set of Geometric Points
- Bounded Set of Numbers
- Box-and-Whisker Plot
- Boxplot
- Braces
- Brackets
- Cardinal Numbers
- Cardinality
- Cartesian Coordinates
- Cartesian Form
- Categorical Data
- Cavalieri’s Principle
- Ceiling Function
- Center of Rotation
- Centers of a Triangle
- Central Angle
- Centroid
- Centroid Formula
- Ceva’s Theorem
- Cevian
- Cevian Theorem
- Change of Base Formula
- Chi-Square Test
- Chord
- Circle
- Circle Graph (Pie Chart)
- Circular Cone
- Circular Cylinder
- Circumcenter
- Circumcircle
- Circumference
- Circumscribable
- Circumscribed
- Coefficient
- Coefficient of Determination (R²)
- Coincident
- Collinear
- Combination
- Combination Formula
- Combinatorics
- Common Logarithm
- Commutative
- Complement of a Set
- Complement of an Angle
- Complement of an Event
- Complementary Angles
- Composite
- Composite Number
- Composition
- Compound Interest
- Compression
- Compression of a Geometric Figure
- Compression of a Graph
- Compute
- Concave
- Concentric
- Concurrent
- Conditional Equation
- Conditional Probability
- Cone
- Cone Angle
- Confidence Interval
- Congruence Tests for Triangles
- Congruent
- Conic Sections
- Conjugate Pair Theorem
- Conjugates
- Consecutive Interior Angles
- Consistent System of Equations
- Constant
- Constant Function
- Constant of Proportionality
- Constant Polynomial
- Continuous
- Continuous Function
- Continuously Compounded Interest
- Convex
- Coordinate Grid
- Coordinate Plane
- Coordinates
- Coplanar
- Correlation
- Correlation Coefficient
- Correlation vs. Causation
- Corresponding
- Cost Function
- Countable
- Countably Infinite
- CPCFC
- CPCTC
- Cross Multiplication
- Cross Section
- Cube
- Cubic Polynomial
- Cumulative Frequency
- Cylinder
- Decagon
- Decay Factor
- Deciles
- Decimal
- Decreasing Function
- Degenerate
- Degree
- Degree of a Polynomial
- Degree of a Term
- Denominator
- Dependent Events
- Dependent Variable
- Descartes' Rule of Signs
- Diagonal of a Polygon
- Diameter of a Circle or Sphere
- Diametrically Opposed
- Difference
- Difference of Cubes
- Difference of Squares
- Digit
- Dihedral Angle
- Dilation
- Dilation of a Geometric Figure
- Dilation of a Graph
- Dimensional Analysis
- Dimensions
- Direct Variation
- Discontinuity
- Discontinuous Function
- Discrete
- Disjoint Sets
- Disk
- Distance Formula
- Distance from a Point to a Line
- Distinct
- Distribute
- Distributing Rules
- Distributive Property
- Divisibility Rules
- Dodecagon
- Dodecahedron
- Domain
- Domain of Definition
- Dot Plot
- Double Cone
- Doubling Time
- e
- Edge of a Polyhedron
- Element of a Set
- Ellipse
- Elliptic Geometry
- Empirical Rule (68-95-99.7 Rule)
- Empty Set
- End Behavior
- Equation
- Equation of a Line
- Equation vs. Expression
- Equiangular Triangle
- Equidistant
- Equilateral Triangle
- Equivalence Properties of Equality
- Equivalence Relation
- Equivalent Systems of Equations
- Euclidean Distance
- Euclidean Geometry
- Euler Line
- Euler's Formula (Polyhedra)
- Evaluate
- Even Function
- Even Number
- Event
- Existential Quantifier
- Expected Value
- Experiment
- Experimental Probability
- Explicit Formula of a Sequence
- Exponent
- Exponent Rules
- Exponential Decay
- Exponential Equation
- Exponential Function
- Exponential Growth
- Exponential Regression
- Exponentiation
- Expression
- Exterior Angle of a Polygon
- Exterior Angle Theorem
- Extrapolation
- Extrema
- Extreme Values of a Polynomial
- Extremum
- Face of a Polyhedron
- Factor of a Polynomial
- Factor of an Integer
- Factor Theorem
- Factor Tree
- Factorial
- Factoring Rules
- Finite
- First Quartile
- Five Number Summary
- Fixed
- Floor Function
- Focus (conic section)
- Formula
- Fractal
- Fraction
- Fraction Rules
- Frequency Table
- Frustum of a Cone or Pyramid
- Function
- Function Notation
- Function Operations
- Fundamental Counting Principle
- Fundamental Theorem of Algebra
- Fundamental Theorem of Arithmetic
- Future Value
- Geometric Figure
- Geometry
- Glide Reflection
- Golden Mean
- Golden Rectangle
- Golden Spiral
- Googol
- Googolplex
- Graph of an Equation or Inequality
- Graph Theory
- Graphic Methods
- Gravity
- Great Circle
- Greatest Common Factor
- Greek Alphabet
- Growth Factor
- Half-Life
- Heptagon
- Heron’s Formula
- Hexadecimal
- Hexagon
- Hexahedron
- Histogram
- HL Congruence
- HL Similarity
- Hole (in a Graph)
- Homogeneous System of Equations
- Horizontal
- Horizontal Asymptote
- Horizontal Line Equation
- Horizontal Line Test
- Horizontal Reflection
- Horizontal Shift
- Horizontal Shrink
- Horizontal Stretch
- Hyperbola
- Hyperbolic Geometry
- Hyperbolic Trigonometry
- Hypotenuse
- Icosahedron
- Identity
- Identity of an Operation
- Identity Property of Addition
- Identity Property of Multiplication
- Image of a Transformation
- Impossible Event
- Improper Fraction
- Incenter
- Inconsistent System of Equations
- Increasing Function
- Independent Events
- Independent Variable
- Inequality
- Infinite
- Infinitesimal
- Infinity
- Inradius
- Inscribed Angle in a Circle
- Inscribed Circle
- Integers
- Interest
- Interior
- Interior Angle
- Interpolation
- Interquartile Range
- Intersection
- Invariant
- Inverse
- Inverse Function
- Inverse Operations
- Inverse Variation
- Irrational Numbers
- Isometry
- Isosceles Trapezoid
- Isosceles Triangle
- Iterative Process
- Joint Variation
- Kite
- Lateral Surface
- Lateral Surface Area
- Law of Large Numbers
- Leading Coefficient
- Leading Coefficient Test
- Leading Term
- Least Common Denominator
- Least Common Multiple
- Least-Squares Regression Equation
- Least-Squares Regression Line
- Leg of a Right Triangle
- Leg of a Trapezoid
- Leg of an Isosceles Triangle
- Like Terms
- Line
- Line of Best Fit
- Line Segment
- Linear
- Linear Combination
- Linear Equation
- Linear Factorization
- Linear Fit
- Linear Inequality
- Linear Pair of Angles
- Linear Polynomial
- Linear Programming
- Linear Regression
- Linear System of Equations
- Literal Equation
- Locus
- Logarithm
- Logarithm Rules
- Logarithmic Equation
- Logical Equivalence
- Logistic Growth
- Lower Bound of a Set
- Major Arc
- Major Axis of a Hyperbola
- Major Axis of an Ellipse
- Major Diameter of an Ellipse
- Margin of Error
- Mathematical Model
- Mean
- Mean Absolute Deviation (MAD)
- Measure of an Angle
- Measurement
- Median of a Set of Numbers
- Median of a Trapezoid
- Median of a Triangle
- Member of an Equation
- Mensuration
- Midpoint
- Midpoint Formula
- Midsegment
- Minor Arc
- Minor Axis of a Hyperbola
- Minor Axis of an Ellipse
- Minor Diameter of an Ellipse
- Minute
- Mixed Number
- Möbius Strip
- Mode
- Monomial
- Multiplication Rule
- Multiplicative Inverse of a Number
- Multiplicative Property of Equality
- Multiplicity
- Multivariable
- Mutually Exclusive
- n Dimensions
- n-gon
- Natural Logarithm
- Natural Numbers
- Negation
- Negative Direction
- Negative Exponents
- Negative Number
- Negative Reciprocal
- Negatively Associated Data
- Net (Geometry)
- Non-Adjacent
- Non-Euclidean Geometry
- Nonagon
- Noncollinear
- Nonnegative
- Nontrivial
- Nonzero
- Normal Distribution
- Null Hypothesis
- Number Line
- Numerator
- Oblique
- Oblique Asymptote
- Oblique Cone
- Oblique Cylinder
- Oblique Prism
- Oblique Pyramid
- Obtuse Angle
- Obtuse Triangle
- Octagon
- Octahedron
- Octants
- Odd Function
- Odd Number
- Odds
- Odds Against
- Odds in Favor
- Odds in Gambling
- One Dimension
- One-to-One Function
- Order of Operations (PEMDAS)
- Ordinal Numbers
- Ordinate
- Origin
- Orthocenter
- Outcome
- Outlier
- Outlier Rule (1.5 x IQR)
- Oval
- Overdetermined System of Equations
- p-value
- Paired Data
- Parallel Lines
- Parallel Planes
- Parallel Postulate
- Parallel Slopes
- Parallelepiped
- Parallelogram
- Parameter (Statistics)
- Parent Functions
- Parentheses
- Partition of a Set
- Pentagon
- Per Annum
- Percent / Percentage
- Percent Change
- Percent Error
- Percentile
- Perfect Number
- Perfect Square
- Perimeter
- Permutation
- Permutation Formula
- Perpendicular
- Perpendicular Bisector
- Perpendicular Slopes
- Pi
- Piecewise Continuous Function
- Piecewise Function
- Piecewise Linear Function
- Place Value
- Plane
- Plane Figure
- Plane Geometry
- Platonic Solids
- Point
- Point of Symmetry
- Point-Slope Equation of a Line
- Polygon
- Polygon Interior
- Polyhedron
- Polynomial
- Polynomial Facts
- Polynomial Function
- Polynomial Inequality
- Polynomial Long Division
- Population
- Positive Direction
- Positive Number
- Positively Associated Data
- Power
- Pre-Image of a Transformation
- Precision
- Present Value
- Prime Factorization
- Prime Number
- Principal
- Prism
- Probability
- Probability Distribution
- Product
- Projectile Motion Formula
- Proper Fraction
- Proper Subset
- Properties of Equality
- Proportion
- Proportional
- Pyramid
- Pythagorean Identities
- Pythagorean Theorem
- Pythagorean Triple
- Quadrants
- Quadrilateral
- Quadruple
- Quantitative Data
- Quartic Polynomial
- Quartiles
- Quintic Polynomial
- Quintiles
- Quintuple
- Quotient
- Radian
- Radical
- Radicand
- Radius of a Circle or Sphere
- Random Sample
- Random Variable
- Range
- Rate of Change
- Ratio
- Rational Exponents
- Rational Numbers
- Rational Root Theorem
- Ray
- Real Numbers
- Rectangle
- Rectangular Parallelepiped
- Recursion
- Recursive Formula
- Reduce a Fraction
- Reflection
- Reflexive Property of Equality
- Regression
- Regression Equation
- Regular Polygon
- Regular Prism
- Regular Pyramid
- Relation
- Relative Frequency
- Relatively Prime
- Remainder
- Remainder Theorem
- Removable Discontinuity
- Residual
- Residual Plot
- Restricted Domain
- Restricted Function
- Rhombus
- Right Angle
- Right Circular Cone
- Right Circular Cylinder
- Right Cone
- Right Cylinder
- Right Prism
- Right Pyramid
- Right Regular Prism
- Right Regular Pyramid
- Right Square Prism
- Right Triangle
- Rigid Transformation
- Root
- Root Mean Square
- Root of a Number
- Rotation
- Rounding a Number
- Sample Space
- Sampling
- Sampling Bias
- SAS Congruence
- SAS Similarity
- Satisfy
- Scale Factor
- Scalene Triangle
- Scatterplot
- Scientific Notation
- Secant Line
- Second
- Sector of a Circle
- Segment of a Circle
- Self-Similarity
- Semicircle
- Semiperimeter
- Set
- Set Braces
- Set Subtraction
- Shift
- Side of a Polygon
- Sigmoid Function
- Significance Level (Alpha)
- Significant Digits
- Similar
- Similarity Tests for Triangles
- Simple Interest
- Simplify
- Simultaneous Equations
- Skew Lines
- Slant Height
- Slope Formula
- Slope of a Line
- Slope-Intercept Equation of a Line
- Solid
- Solid Geometry
- Solution
- Solve
- Solve Analytically
- Solve Graphically
- Speed
- Sphere
- Square
- Square Root
- Square System of Equations
- SSA
- SSS Congruence
- SSS Similarity
- Standard Deviation
- Standard Form for the Equation of a Line
- Standard Position
- Statistic
- Stemplot
- Step Function
- Straight Angle
- Strict Inequality
- Subset
- Sum
- Sum of Cubes
- Superset
- Supplement
- Supplementary Angles
- Surd
- Sure Event
- Surface
- Surface Area
- Symmetric
- Symmetric Property of Equality
- Symmetric with Respect to the Origin
- Symmetric with Respect to the x-axis
- Symmetric with Respect to the y-axis
- Synthetic Division
- Synthetic Substitution
- Takeout Angle
- Tangent Line
- Term
- Tessellate
- Tetrahedron
- Theoretical Probability
- Third Quartile
- Three Dimensional Coordinates
- Three Dimensions
- Time Series
- Torus
- Transcendental Numbers
- Transformations
- Transitive Property of Equality
- Transitive Property of Inequalities
- Translation (Geometry)
- Transversal
- Trapezium
- Trapezoid
- Tree Diagram
- Triangle
- Triangle Inequality
- Triangle Inequality with Absolute Value
- Triangulation
- Trichotomy
- Trinomial
- Triple
- Trivial
- Truncated Cone or Pyramid
- Truncated Cylinder or Prism
- Truncating a Number
- Truth Table
- Twin Primes
- Two Dimensions
- Two Intercept Form for the Equation of a Line
- Two-Way Table
- Type I Error
- Type II Error
- Unbounded Set of Numbers
- Uncountable
- Undecagon
- Undefined Slope
- Underdetermined System of Equations
- Uniform
- Union
- Unit Rate
- Univariate Data
- Universal Quantifier
- Upper Bound of a Set
- Variable
- Variance
- Varignon Parallelogram of a Quadrilateral
- Velocity
- Venn Diagrams
- Verify a Solution
- Vertex
- Vertical
- Vertical Angles
- Vertical Asymptote
- Vertical Line Equation
- Vertical Line Test
- Vertical Reflection
- Vertical Shift
- Vertical Shrink
- Vertical Stretch
- Vertices of a Hyperbola
- Vertices of an Ellipse
- Vinculum
- Volume
- Weighted Average
- Weighted Mean
- Whole Numbers
- x-axis
- x-intercept
- x-y Plane
- x-z Plane
- y-axis
- y-intercept
- y-z Plane
- z-intercept
- Z-Score
- Zero
- Zero Dimensions
- Zero of a Function
- Zero Property of Multiplication
- Zero Slope
