Math Glossary
Plain-language definitions for the terms behind WorkedMath's calculators. Each one links to the calculator that puts it to use.
- Absolute Value
The distance a number is from zero, always expressed as a positive value.
- Arc Length
The distance along a curved part (arc) of a circle.
- Binary Number
A number written using only the digits 0 and 1, the base-2 counting system computers use.
- Chi-Square Test
A statistical test that checks whether observed data matches what you'd expect.
- Cone
A 3D shape with a circular base that tapers smoothly to a single point.
- Cube Root
The number that, multiplied by itself three times, gives the original number.
- Cylinder
A 3D shape with two parallel circular bases connected by a curved surface.
- Determinant
A single number calculated from a square matrix that reveals key properties about it.
- Discount
A reduction from a product's original price, usually expressed as a percentage.
- Discriminant
The part of the quadratic formula (b² − 4ac) that tells you what kind of roots to expect.
- Distance Formula
A formula that finds the straight-line distance between two points on a coordinate plane.
- Domain and Range
The domain is every valid input to a function; the range is every possible output.
- Expanded Form
Writing a number as the sum of the value of each of its digits.
- Exponent
A number that shows how many times to multiply a base by itself.
- Exponential Growth
Growth where a quantity increases by the same percentage over equal time periods.
- Factor
A whole number that divides evenly into another number.
- Factorial
The product of every whole number from 1 up to a given number.
- Factoring (Algebra)
Rewriting an expression as a product of simpler expressions that multiply back to the original.
- GCF (Greatest Common Factor)
The largest number that divides evenly into two or more numbers.
- Golden Ratio
A special number, approximately 1.618, where the ratio of a whole to its larger part equals the ratio of the larger part to the smaller part.
- GPA (Grade Point Average)
A number, usually on a 4.0 scale, that summarizes a student's overall academic performance.
- Hexagon
A six-sided polygon.
- Hypotenuse
The longest side of a right triangle, opposite the right angle.
- Inverse Function
A function that reverses the effect of another function.
- Korean Age
A traditional East Asian age-counting system where a newborn starts at age 1 and everyone gains a year together on January 1st.
- Law of Cosines
A formula that finds a triangle's unknown side or angle when the law of sines doesn't apply directly.
- Law of Sines
A formula relating a triangle's side lengths to the sines of their opposite angles.
- LCD (Least Common Denominator)
The smallest number that can serve as a shared denominator for two or more fractions.
- LCM (Least Common Multiple)
The smallest number that two or more numbers all divide into evenly.
- Linear Equation
An equation whose graph is a straight line, with no variable raised above the first power.
- Logarithm
The exponent you'd need to raise a base to, to get a given number.
- Long Division
A step-by-step method for dividing large numbers by hand, one digit at a time.
- Markup
The amount added to a product's cost to set its selling price, usually expressed as a percentage of the cost.
- Matrix
A rectangular grid of numbers arranged in rows and columns.
- Mean, Median, and Mode
The three most common ways to describe the "center" of a data set.
- Midpoint
The point exactly halfway between two other points.
- Mixed Number
A number written as a whole number combined with a proper fraction.
- Percentile
A ranking that shows what share of a data set falls below a given value.
- Perfect Square
A number that's the square of a whole number.
- Perimeter
The total distance around the outside edge of a two-dimensional shape.
- Permutation
The number of ways to arrange a set of items where order matters.
- Point-Slope Form
A way of writing a linear equation as y − y₁ = m(x − x₁), using one known point and the slope.
- Polynomial
An expression made of variables raised to whole-number powers, combined with addition and subtraction.
- Prime Number
A whole number greater than 1 with exactly two factors: 1 and itself.
- Proportion
An equation stating that two ratios are equal.
- Pythagorean Theorem
For a right triangle, a² + b² = c², where c is the hypotenuse.
- Quadratic Equation
An equation of the form ax² + bx + c = 0, where a is not 0.
- Quartile
One of three values that split a sorted data set into four equal parts.
- Ratio
A comparison of two quantities showing how many times one contains the other.
- Rationalizing the Denominator
Rewriting a fraction so its denominator no longer contains a square root.
- Remainder
What's left over after dividing one number by another as evenly as possible.
- Roman Numerals
An ancient number system using letters (I, V, X, L, C, D, M) instead of digits.
- Sales Tax
A percentage-based tax added to the price of goods or services at the point of sale.
- Sample Size
The number of observations needed in a study to get a reliable result.
- Scale Factor
The ratio between the size of a scaled shape and the original shape.
- Scientific Notation
A way of writing very large or very small numbers as a number between 1 and 10 times a power of 10.
- Simple Interest
Interest calculated only on the original loan or deposit amount, not on any interest already earned.
- Slope
A measure of how steep a line is, expressed as rise over run.
- Slope-Intercept Form
A way of writing a linear equation as y = mx + b, where m is the slope and b is the y-intercept.
- Sphere
A perfectly round 3D shape where every point on the surface is the same distance from the center.
- Standard Deviation
A measure of how spread out a set of numbers is from its average.
- Surface Area
The total area covering the outside of a 3D shape.
- Synthetic Division
A shortcut method for dividing a polynomial by a linear factor (x − c).
- System of Equations
A set of two or more equations sharing the same variables, solved together.
- T-Test
A statistical test that checks whether a sample's average is meaningfully different from an expected value.
- Trapezoid
A four-sided shape with exactly one pair of parallel sides.
- Variance
The average of the squared differences between each value and the mean.
- Vertex Form
A way of writing a quadratic equation as y = a(x − h)² + k, where (h, k) is the parabola's vertex.
- Weighted Average
An average where some values count more than others.
- Z-Score
A measure of how many standard deviations a value sits from the mean.