Mathematics key terms

A branching diagram that shows the possible outcomes at each stage of a process.

The overall direction in which time series values generally move over time.

One repetition of a probability experiment, such as one roll of a die.

A figure formed by three line segments joining three vertices.

A number of objects that can be arranged in a triangular pattern; the $n$th triangular number is $\frac{n(n+1)}{2}$.

A function whose output is the sine, cosine or tangent of an angle.

A relationship between an acute angle and two side lengths in a right-angled triangle, such as sine, cosine or tangent.

Removing digits after a chosen place without changing the last digit kept.

The single minimum or maximum point of a quadratic graph, where the curve changes direction.

A table that classifies the same results in two ways, with row and column totals.

A sample collected without a systematic tendency to favour or exclude particular outcomes.

A value that has no defined numerical result, such as division by zero.

An assumption about how a probability situation works, such as whether selections are random or whether an object is replaced.

Data shown as individual values rather than combined into class intervals.

The set of elements that belong to $A$, to $B$, or to both sets.

Every whole number greater than 1 can be expressed as a product of primes in exactly one way, apart from the order of the factors.

The agreed quantity used to state a measurement, such as a metre or a second.

A method that finds the amount corresponding to one unit before scaling to the required number of units.

A method of converting units by multiplying by conversion factors equal to 1, so that unwanted units cancel.

A circle of radius 1 centred at the origin, used to connect angles with sine and cosine values.

One of the equal parts made when a whole is divided by the denominator.

The cost of one unit of a product, such as £ per kilogram or pence per 100 ml.

A ratio in which one selected part has been made equal to 1, such as $1:n$.

One numerical variable recorded for each member of a data set.

The complete set of elements being considered in a question, often shown by a rectangle in a Venn diagram.

A letter or symbol representing a value that is not yet known.

The boundary at the top of the range of possible original values; for ordinary rounding, this boundary is excluded from the error interval.

A value found using limits of accuracy so that no possible result lies above it.

A value that divides ordered data so that approximately three quarters of the observations lie at or below it.

The value approximately three-quarters of the way through an ordered distribution, with about 75% of the data below it.