### 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 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 4x + 5y2 + 3z, the coefficients for x, y2 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

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.

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 (a2 + b2 = c2)

#### Q

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

#### R

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

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.