Mathematics key terms

A whole number greater than 1 with exactly two positive factors: 1 and itself.

The initial amount borrowed or invested on which interest is calculated.

The positive square root represented by the symbol $\sqrt{\phantom{x}}$; for example, $\sqrt{25}=5$.

The agreed sequence in which the operations in a calculation are performed.

A solid with two congruent, parallel polygonal ends and the same cross-section throughout its length.

A number from 0 to 1 that measures how likely an event is to occur.

A set of probabilities showing how likely each possible outcome is.

A process with an uncertain outcome, such as tossing a coin or rolling a dice.

A branching representation that shows the possible outcomes of successive events and the probability on each branch.

The result of multiplying factors together.

Writing factors multiplied together, using powers to shorten repeated factors; for example, $2\times2\times3=2^2\times3$.

A counting rule which multiplies the number of choices at successive stages.

The amount by which a selling price exceeds its cost price.

The right-angled shadow of a line on a plane, formed by dropping a perpendicular from the line's raised endpoint to the plane.

A logically connected sequence of true mathematical statements that establishes a result in every case covered by the claim.

A proof that assumes a statement is false and shows that this assumption leads to an impossibility.

A fraction whose numerator is smaller than its denominator, such as $\frac{3}{5}$.

A statement that follows from a shape’s definition or from facts already proved about the shape.

An equality between two ratios, such as $2:3=6:9$.

A change in which the same multiplier is applied to every value, so the quantities remain in a constant ratio.

The symbol $\propto$, meaning “is proportional to”. It must be replaced by an equals sign and a constant of proportionality before values are calculated.

An instrument marked in degrees, used to measure and draw angles.

A solid with a polygonal base and triangular faces that meet at one vertex called the apex.

The rule $a^2+b^2=c^2$ for a right-angled triangle, where is its hypotenuse.

One of the four regions formed by the $x$-axis and $y$-axis.

An equation that can be written as $ax^2+bx+c=0$, where $$, and are constants and .

A polynomial expression whose highest power of the variable is 2, usually written in the form $ax^2+bx+c$ where $a\ne0$.

A formula for solving $ax^2+bx+c=0$: $$.

A function whose highest power of the variable is 2, usually written in the form $y=ax^2+bx+c$, where .

A graph of an equation containing an $x^2$ term as its highest power of $x$. It has a U-shaped or upside-down U-shaped curve.