Edexcel GCSE Mathematics key terms

A notation that marks recurring digits with dots. One dot marks a single recurring digit; for a longer block, dots mark its first and last digits.

A straight line segment where two flat faces meet.

A two-dimensional view of a three-dimensional object seen straight on from a specified direction, such as the front or side.

A method that combines equations by addition or subtraction so that one variable cancels.

Empirical data consists of values obtained from observations or measurements rather than from a theoretical model.

A probability found from the results of an experiment or observed data.

A transformation that multiplies every displacement from a fixed centre by one scale factor.

The process of listing every member or possible outcome without omissions or repetitions.

Outcomes that each have the same probability of occurring.

A mathematical statement saying that two expressions are equal.

At the same distance from two or more specified points, lines or other objects.

A triangle with three equal sides.

A value that an iterative process approaches and that remains unchanged when put back into the rule.

Expressions that have the same value for every permissible choice of their variables.

A ratio obtained by multiplying or dividing every part by the same positive number.

Ratios that have the same value because every part has been multiplied or divided by the same non-zero number.

The range of possible exact values represented by a rounded value, written using inequalities.

An approximate value obtained from available information rather than an exact count or measurement.

A straight line drawn to represent the overall trend of the points on a scatter graph.

An outcome or collection of outcomes whose probability is being considered.

A value written without rounding, usually using integers, fractions and surds rather than a decimal approximation.

A value that a variable cannot take because it would make an original denominator zero or a divisor equal to zero.

A set of outcomes or events that covers every possible result, so at least one must occur.

To multiply out brackets so that an equivalent expression is written without those brackets.

A calculated number expected in a category over many cases, found by multiplying the total number of trials by the relevant probability.

A function in which the variable appears as an exponent; for example, $y=k^x$ for a positive constant $k$.

A relationship in which equal changes in the input multiply the output by the same factor.