Edexcel GCSE Mathematics key terms

A scale written in words, such as “1 cm represents 5 km”.

A numerical value that summarises data, such as a mean, median, mode or range.

A graph whose points form a straight line and can be described by a linear equation. A non-vertical straight line has a constant gradient; a vertical straight line has undefined gradient.

The variable written alone on one side of a formula.

To replace a variable with a known value in order to evaluate a formula.

A method that replaces a variable with an equal expression taken from another equation.

An angle is subtended by an arc or chord when its two arms meet the endpoints of that arc or chord.

Two angles whose sum is $180^\circ$; supplementary angles have equal positive sine values.

An exact irrational root that cannot be simplified to a rational number, such as $\sqrt2$.

A flat or curved part of the outside of a 3D shape.

The total area of all the exposed faces and curved surfaces on the outside of a three-dimensional solid, measured in square units.

An organised method of recording every possible outcome exactly once.

A straight line drawn to match the direction of a curve at a chosen point, used to estimate the curve's gradient there.

One of ten equal parts of a whole, written as 0.1.

The value at a particular position in a sequence; $u_n$ denotes the term at position $n$.

A decimal with a finite number of digits after the decimal point, such as $0.375$.

A rule that calculates the next term using the current term.

A point chosen away from a boundary line and substituted into an inequality to identify which side satisfies it.

A probability calculated from a mathematical model, such as equally likely outcomes for a fair die.

One of one thousand equal parts of a whole, written as 0.001.

Data made up of observations of the same quantity recorded at different times.

A graph showing how a quantity changes over time, with time on the horizontal axis and consecutive plotted points usually joined by straight lines.

The principal together with all the interest charged or earned.

A movement that shifts every point of a shape the same distance in the same direction, without turning or resizing it.

A line that crosses two or more other lines.

A four-sided shape with one pair of parallel sides.

The overall long-term direction of a time series, such as increasing, decreasing or remaining broadly level.

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