Glossary

Definitions of mathematical and scientific terms.

Math & Science Glossary

Clear definitions of 63 terms used across our calculators, formula library, and educational articles. Use this reference when you encounter unfamiliar notation or concepts.

How to Use the Glossary

Terms are organized alphabetically below. Each entry includes a concise definition and a category badge (Algebra, Geometry, Statistics, etc.). For deeper explanations, follow links to related calculators and articles.

Categories Covered

Algebra (10)Chemistry (5)Finance (6)Geometry (6)Math (11)Physics (9)Statistics (16)

All Terms A–Z

Absolute Value
The distance of a number from zero on the number line, always non-negative. Written |x|; for example |−5| = 5. Algebra
Algorithm
A step-by-step procedure for solving a problem. The Euclidean algorithm finds GCF efficiently. Math
Amortization
Spreading a loan repayment over time into equal periodic payments covering principal and interest. Finance
ANOVA
Analysis of Variance — a statistical method comparing means across multiple groups. Statistics
APR
Annual Percentage Rate — the yearly cost of borrowing including interest and certain fees, expressed as a percentage. Finance
Arc Length
The distance along a curved path. For a circle: L = rθ where θ is in radians. Geometry
Arithmetic Mean
The average of a data set: sum of values divided by count. Sensitive to outliers. Statistics
Asymptote
A line a curve approaches but never touches. Horizontal asymptotes appear in exponential decay. Algebra
Avogadro's Number
6.022 × 10²³ — the number of particles in one mole of a substance. Chemistry
Binomial
An expression with two terms, such as (a + b). Binomial coefficients appear in combinations. Algebra
Coefficient
A numerical factor multiplying a variable. In 5x², 5 is the coefficient. Algebra
Combination (nCr)
Ways to choose r items from n when order does not matter: C(n,r) = n! / [r!(n−r)!]. Statistics
Compound Interest
Interest calculated on principal plus previously earned interest — growth accelerates over time. Finance
Confidence Interval
A range of values likely to contain the true population parameter at a stated confidence level. Statistics
Correlation
A measure of linear association between two variables, ranging from −1 to +1 (Pearson r). Statistics
Cosine
Trigonometric ratio: adjacent/hypotenuse in a right triangle. cos(0°) = 1. Math
Density
Mass per unit volume (ρ = m/V), typically kg/m³. Distinguishes buoyancy and material identification. Physics
Determinant
A scalar value from a square matrix indicating invertibility and area/volume scaling factor. Algebra
Discriminant
b² − 4ac in a quadratic equation. Positive: two real roots; zero: one; negative: complex roots. Algebra
Dilution
Reducing concentration by adding solvent. M₁V₁ = M₂V₂ when moles of solute are conserved. Chemistry
EMI
Equated Monthly Installment — fixed loan payment covering principal and interest each month. Finance
Exponent
Shows how many times a base is multiplied by itself. x³ means x × x × x. Math
Factorial (n!)
Product of all positive integers up to n. 5! = 120. Used in permutations and combinations. Statistics
Force
A push or pull causing acceleration. Newton's second law: F = ma (newtons = kg·m/s²). Physics
GCF (Greatest Common Factor)
Largest integer dividing two or more numbers without remainder. GCF(48, 18) = 6. Math
Gradient
The slope of a line or surface. Steeper gradients mean faster change. Geometry
Heron's Formula
Area of a triangle from three sides: A = √[s(s−a)(s−b)(s−c)] where s is semi-perimeter. Geometry
Hypotenuse
The longest side of a right triangle, opposite the right angle. Geometry
Imaginary Unit (i)
Defined as i = √(−1). Enables complex numbers a + bi. Algebra
Inflation
The rate at which purchasing power of money decreases over time. Real return ≈ nominal − inflation. Finance
Kinetic Energy
Energy of motion: KE = ½mv². Doubling speed quadruples kinetic energy. Physics
LCM (Least Common Multiple)
Smallest positive integer divisible by all given numbers. LCM(4, 6) = 12. Math
Logarithm
The inverse of exponentiation. log₁₀(100) = 2 because 10² = 100. Math
Margin of Error
Half-width of a confidence interval. MOE = z × (s/√n) for means. Statistics
Matrix
A rectangular array of numbers used in linear algebra for systems of equations and transformations. Algebra
Mean
Sum of values divided by count. Also called arithmetic average. Statistics
Median
Middle value when data is sorted. Robust to outliers compared to mean. Statistics
Molarity
Concentration in moles of solute per liter of solution (mol/L or M). Chemistry
Mole
SI unit for amount of substance. One mole contains Avogadro's number of particles. Chemistry
Momentum
Product of mass and velocity (p = mv). Conserved in closed systems. Physics
Normal Distribution
Bell-shaped probability distribution defined by mean μ and standard deviation σ. Statistics
Ohm's Law
V = IR — voltage equals current times resistance in resistive circuits. Physics
pH
Measure of acidity: pH = −log₁₀[H⁺]. pH 7 is neutral; below 7 acidic, above 7 basic. Chemistry
Percentage
Parts per hundred. 25% = 25/100 = 0.25. Math
Permutation (nPr)
Arrangements of r items from n when order matters: P(n,r) = n! / (n−r)!. Statistics
Polynomial
Expression with multiple terms of non-negative integer powers, e.g. 3x² + 2x − 1. Algebra
Potential Energy
Stored energy due to position: PE = mgh for gravitational potential near Earth's surface. Physics
Power
Rate of doing work or transferring energy. P = W/t or P = VI in electricity. Physics
Prime Number
Integer greater than 1 divisible only by 1 and itself. 2 is the only even prime. Math
Probability
Likelihood of an event, from 0 (impossible) to 1 (certain). P(A) = favorable / total for equally likely outcomes. Statistics
Profit Margin
Percentage of revenue retained as profit: (Revenue − Cost) / Revenue × 100%. Finance
Pythagorean Theorem
a² + b² = c² for right triangles, where c is the hypotenuse. Geometry
Quadratic Equation
Equation of form ax² + bx + c = 0. Solved by factoring, completing the square, or quadratic formula. Algebra
Radians
Angle unit where 2π radians = 360°. Required in many calculus and physics formulas. Math
Regression
Fitting a mathematical model (often a line) to data to predict one variable from another. Statistics
Significant Figures
Digits conveying measurement precision. Result should not imply more precision than the least precise input. Math
Sine
Trigonometric ratio: opposite/hypotenuse in a right triangle. Math
Slope
Steepness of a line: m = (y₂ − y₁)/(x₂ − x₁). Positive slopes rise left to right. Geometry
Standard Deviation
Measure of data spread around the mean. Sample SD uses divisor n−1. Statistics
Variance
Average squared deviation from the mean. Standard deviation is the square root of variance. Statistics
Velocity
Rate of change of position with direction. Speed is magnitude only. Physics
Work
Energy transferred by force over distance: W = Fd cos θ when force and displacement are at angle θ. Physics
Z-Score
Standard score: z = (x − μ)/σ. Measures how many standard deviations a value is from the mean. Statistics