### Welcome to our list of math terms. An online math dictionary!

Below is a list of math terms that are regularly used. See this as a basic online math dictionary. Use this as a quick reference for standard math terms.

#### A

**Absolute value**

The magnitude of a number. It is the number with the sign (+ or -) removed and is symbolised using two vertical straight lines ( |5| ). Also called modulus.

**Abstract number**

A number with no associated units.

**Acute angle **

An angle less than 90°.

**Adjacent **

Adjacent sides are next to each other and are joined by a common vertex.

**Algebra**

Algebra is the branch of mathematics that uses symbols or letters to represent variables, values or numbers.

**Angle **

An angle is formed when two straight lines cross or meet each other at a point.

**Approximate **

An approximate value is a value close to the actual value of a number.

**Arc **

Part of a circumference of a circle.

**Area **

The amount of space a shape takes up. E.g. the area of the lawn is 35 square metres.

**Asymmetrical **

A shape which has no lines of symmetry.

**Average **

The sum of several quantities divided by the number of quantities (also called mean).

**Axiom**

A proposition that is not actually proved or demonstrated, but is considered to be self-evident and universally accepted based on assumption.

#### B

**Bell curve**

The shape of the graph that indicates a normal distribution in probability and statistics

**Binary operation**

An operation that is performed on just two elements of a set at a time.

**Bisect **

To divide an angle or shape exactly in half.

**Boolean algebra or logic**

A type of algebra which can be applied to the solution of logical problems and mathematical functions, in which the variables are logical rather than numerical, and in which the only operators are AND, OR and NOT

**Brackets **

Used to determine the order in which operations are carried out. For instance, 3 + 4 x 2 = 11 but (3 + 4) x 2 = 14.

#### C

**Calculate **

To work out the value of something. This does not have to mean you need a calculator!

**calculus (infinitesimal calculus)**

A branch of mathematics involving derivatives and integrals, used to study motion and changing values. It involves determining areas (integration) and tangents (differentiation), which are mutually inverse.

**Chord**

A straight line joining two points on a curve or a circle.

**Circle**

A circle is defined as the set of points at a given distance (or radius) from its centre.

**Circumference **

The perimeter of a circle.

**Coefficients**

The factors of the terms (i.e. the numbers in front of the letters) in a mathematical expression or equation, e.g. in the expression 4*x* + 5*y*^{2} + 3*z*, the coefficients for *x*, *y*^{2} and *z* are 4, 5 and 3 respectively

**Congruent **

If you can place a shape exactly on top of another then they are said to be congruent. You may rotate, reflex or translate the shape.

**Constant **

A letter or symbol whose value always stays the same. The constant Π is a common example.

**coordinate**

The ordered pair that gives the location or position of a point on a coordinate plane, determined by the point’s distance from the *x* and *y* axes, e.g. (2, 3.7) or (-5, 4)

**Cross section**

The end section created when you slice a 3D shape along it’s length.

**Cuboid **

A 3D shape with all sides made from rectangles.

**Cumulative frequency**

A running total of the frequencies, added up as you go along.

#### D

**Denominator **

The bottom part of a fraction.

**Diameter **

The distance across a circle which passes through the centre.

**Difference **

Subtract the smaller value from the larger value to find the difference between two numbers.

**Digit**

In the decimal system, the numbers 0 through 9.

**Distance **

How far away an object is. For example, it is a distance of 3 miles to the city centre.

**Distribution **

How data is shared or spread out.

**Dynamics**

The study of how force produces motion.

#### E

**Equal **

Used to show two quantities have the same value.

**Equation **

Two expressions which have the same value, separated by an ‘=’ sign. E.g. 3y = 9 + y

**Equilateral triangle **

A triangle with all sides and angles the same size.

**Estimate **

To find an approximate answer to a more difficult problem. E.g. 31.2 x 5.94 is roughly equal to 30 x 6 = 180.

**Even number**

A natural number that is divisible by two.

#### F

**Factor **

A number that divides another number exactly. E.g. 4 is a factor of 12.

**Fermat primes**

Prime numbers that are one more than a power of 2

**Fibonacci sequence**

Sequence of integers. where each is the sum of the two preceding it. 1,1,2,3,5,8,13,21,…

**Formula **

An equation used to describe a relationship between two or more variables.

**Fractals**

A geometrical formula represented as by patterns that are repeated at ever decreasing sizes..

**Fraction
**A portion of a whole amount.

**Frequency **

How many times something happens.

#### G

**Gradient **

The slope of a line.

**Geometry
** the part of mathematics concerned with the size, shape and relative position of figures, or the study of lines, angles, shapes and their properties

**Golden ratio (golden ratio)**

The ratio of two quantities 1.618

#### H

**Hyperbola**

A smooth symmetrical curve with two branches produced by the section of a conical surface.

**Hypotenuse **

The longest side on a right angled triangle.

#### I

**Imaginary number**

Are the square roots of negative numbers.

**Infinity
**Having no end or limits.

**Integer**

A whole number.

**Irrational number**

A decimal which is never ending and cannot be represented as decimals.

#### J

**Justify**

To ‘explain’.

#### K

**knot theory**

The study of mathematical knots (knots made with string or rope).

#### L

**LCM ‘lowest common multiple’**

It is the smallest multiple common to a set of numbers. E.g. The LCM of 3 and 4 is 12.

**Loci **

The plural for locus.

**Locus **

A collection of points which are the same distance from another point or line.

**logic**

Mathematical logic the application of the techniques of formal logic to maths and mathematical reasoning.

**Lower range **

The smallest value in a set of data.

#### M

**Magic Square**

a square array of numbers where each row, column and diagonal added up to the same total, known as the magic sum or constant.

**Mandelbrot set**

A set of points in the complex plane, the boundary of which forms a fractal.

**Mean **

An average worked out by adding up a list of numbers and dividing by how many numbers are in the list.

**Median**

The middle value when a list of numbers is put in order from smallest to largest. A type of average.

**Modulus**

A number by which two given numbers can be divided by integer division, and produce the same remainder.

**Multiple **

A number which is part of another number’s times table. E.g. 35 is a multiple of 5.

**Multiplication**

The process of finding the *product* of two quantities.

#### N

**Natural numbers**

The set of positive integers (regular whole counting numbers), sometimes including zero.

**Negative **

A value less than zero.

**Numerator **

The top number in a fraction.

#### O

**Obtuse angle**

An angle between 90 and 180 .

**Odd number **

A number that is not a multiple of 2.

**Operation **

An action which when applied to one or more values gives an output value. The four most common operations are addition. subtraction, multiplication and division.

**Origin**

The point on a graph that represents the point where the *x* and *y *axes meet.

#### P

**Parallel**

Two or more lines which are the same distance apart.

**Parallelogram**

A quadrilateral with two pairs of parallel sides.

**Perimeter**

The distance around a shape.

Perpendicular

Two or more lines which meet at right angles.

**Pi (Π)**

Used when calculating the area and circumference of circles. It is approximately equal to 3.14.

**Positive number**

A number greater than zero.

**plane:**

a flat two-dimensional surface with infinite width and length

**prime numbers:**

A natural number other than 1, evenly divisible only by 1 and itself.

**Prism**

A 3D shape with the same cross section all along its length.

**Probability**

A measure of how likely an event is to occur.

**Product**

The answer when two values are multiplied together.

**Pythagoras theorem**

The square of the hypotenuse of a right angled triangle is equal to the sum of the squares of the two sides (*a*^{2} + *b*^{2} = *c*^{2})

#### Q

**Quadratic equation**

An algebraic equation of the second degree. For example x² + 4x + 6 = 0 is a quadratic equation.

#### R

**Radius**

The distance from the center of a circle to its circumference.

**Rational**

A decimal number which ends or is recurring.

**Reciprocal**

The multiplicative inverse of a number

**Repeating decimal**

A decimal that can be written using a horizontal bar to show the repeating digits.

**Reflex angle**

An angle greater than 180 .

**Regular**

A shape with all sides and angles that are equal.

**Remainder**

The amount left over when a number cannot be divided exactly. For example, 21 divided by 4 is 5 remainder 1.

**Right angle**

An angle of 90 .

**Round**

To reduce the amount of significant figures or decimal places a number has. For example $179 rounded to the nearest $10 is $180.

#### S

**Scale factor**

How many times larger or smaller an enlarged shape will be.

**Segment**

An area of a circle enclosed by a chord.

Sequence

A sequence of numbers which follows a pattern. For example 6, 11, 16, 21, …

**Solid**

A 3D shape.

**Solve**

To find the missing value in an equation.

**Square number**

When an integer is multiplied by itself. Eg 1, 4, 9, 16, 25, 36, 49, 64, 81, 100.

**Stationary point**

Point at which the derivative of a function is zero. It includes maximum and minimum turning points, but not all stationary points are turning points.

**Sum**

The answer when two or more values are added together.

**Surface area**

To total area of all sides.

**Symmetrical**

A shape which has a minimum of 1 line of symmetry.

#### T

**Tangent**

A straight line that just touches a point on a curve.

**Term**

A number, variable or combination of both which forms part of an expression.

**Transformation**

The collective name for reflections, rotations, translations and enlargements.

**Translation**

To move an object from one position to another by sliding in the x-axis followed by the y-axis.

**Triangular number**

A number which can be represented as an equilateral triangle of dots, and is the sum of all the consecutive numbers up to its largest prime factor For example, 1, 3, 6, 10, 15, 21, …

**trigonometry**

The branch of mathematics that studies the trigonometric functions functions (sine, cosine, tangent and their reciprocals)

#### U

**Units**

A quantity used to describe a measurement. Eg kilograms and metres.

**Upper range**

The largest value in a set of data.

#### V

**Value**

A numerical amount or quantity.

**Variable**

A letter which is an empty vessel that can change value.

**vector**

A physical quantity having magnitude and direction, represented by a directed arrow indicating its orientation in space

**vector space
**A three-dimensional area where vectors can be plotted, or a mathematical structure formed by a collection of vectors

**Volume**

The amount an object can hold. E.g. a bottle of cola has a volume of 1 litre.

#### W

**Width**

The distance from side to side. E.g. ‘The pool is 8 metres wide.’

**Whole number**

Zero or any positive number with no fractional parts.

#### X

**X-Axis**

The horizontal axis on a graph. The line going left to right or right to left.

#### Y

Y-Axis

The vertical axis on a graph. The line going from top to bottom.

#### Z

**Z-Axis**

Represents the depth of an object when working with 3D coordinates known as z depth.

**Zermelo-Fraenkel set theory**

The standard form of set theory and the most common foundation of modern mathematics, based on a list of nine axioms.

**Zeta function**

A function based on an infinite series of reciprocals of exponents.