## Glossary - Mathematical words you need to know

A collection of mathematical words and their meanings. It may be useful to print these off and use them as a revision aid. Make sure you understand them all before your exam!

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
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A | |
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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 where symbols or letters are used to represent numbers. |

Angle | An angle is formed when two straight lines cross or meet each other at a point. The size of an angle is measured by the amount one line has been turned in relation to the other. |

Approximate | An approximate value is a value that is 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 | A value to best represent a set of data. There are three types of average - the mean, the median and the mode. |

Axis | An axis is one of the lines used to locate a point in a coordinate system. |

B | |

Bearing | A three digit angle measured from north in a clockwise direction. |

BIDMAS | A way of remembering the order in which operations are carried out. It stands for Brackets - Indices - Division - Multiplication - Addition - Subtraction. |

Bisect | To divide an angle or shape exactly in half. |

Brackets | Used to determine the order in which operations are carried out. For example, 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! |

Centilitre (cl) | A measure of volume. 100 centilitres = 1 litre (100 cl = 1 l). 1 centilitre = 10 millilitres (1 cl = 10 ml). |

Centimetre (cm) | A measure of distance. 1 centimetre = 10 millimetres. (1 cm = 10 mm). 100 centimetres = 1 metre. (100 cm = 1 m). |

Chord | A straight line drawn from one point on the edge of a circle to another. |

Circumference | The perimeter of a circle. |

Coefficient | The number in front of an algebraic symbol. For example the coefficient of 5x is 5. |

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. |

Credit | To add money to a bank account. For example, I had £500 credited to my bank account. |

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

Cube number | The product when an integer is multiplied by itself twice. For example 5 cubed = 5 x 5 x 5 = 125. |

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 | |

Day | A time period of 24 hours. There are 7 days in a week. |

Debit | To take out money from a bank account. For example, £400 was debited from my account. |

Decagon | A ten sided polygon. |

Decimal | Not a whole number or integer. For example, 3.6 or 0.235. |

Decrease | To make an amount smaller. |

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. |

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. |

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 | Any number which is a multiple of 2. Even numbers always end in 2, 4, 6, 8 or 0. |

Expand | To multiply out brackets in an expression. For example, 2(3x + 7) = 6x + 14. |

Expression | A collection of terms which can contain variables (letters) and numbers. E.g. 4pq - q + 7 |

F | |

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

Factorise | To put an expression into brackets by taking out a common factor. For example, 20x + 15y = 5(4x + 3y). |

Figures | Another name for numbers. For example one thousand and fifty in figures is 1050. |

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

Frequency | How many times something happens. Another word for 'total'. |

Frequency density | The frequency divided by the class width. |

G | |

Gradient | How steep a line is. Found by dividing the distance up by the distance across. |

Gram (g) | A measure of mass. 1 gram = 1000 milligrams. (1 g = 1000 mg) |

H | |

HCF | Stands for 'highest common factor'. It is the largest factor common to a set of numbers. E.g. The HCF of 16 and 24 is 8. |

Heptagon | A seven sided polygon. |

Hexagon | A six sided polygon. |

Histogram | A diagram drawn with rectangles where the area is proportional to the frequency and the width is equal to the class interval. |

Hypotenuse | The longest side on a right angled triangle. |

I | |

Increase | To make an amount larger. |

Indices | Another name for powers such as ² or ³. |

Integer | A whole number. |

Inter-quartile range (IQR) | The difference between the upper and lower quartile. |

Irrational | A decimal which is never ending. It must also not be a recurring decimal. |

J | |

Justify | Another word for 'explain'. Often crops up on your maths exam. E.g. 'Calculate the mean and range for each player. Who is the better player Justify your answer.' |

K | |

Kilogram (Kg) | A measure of mass. 1 kilogram = 1000 grams. (1 kg = 1000 g) |

Kilometre (Km) | A measure of distance. 1 kilometre = 1000 metres. (1 km = 1000 m) |

L | |

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

Litre (l) | A measure of volume. 1 litre = 100 centilitres (1 l = 100 cl). 1 litre = 1000 millilitres (1l = 1000 ml). |

Loci | The plural of locus. |

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

Lower range | The smallest value in a set of data. |

M | |

Mean | A type of average found 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. |

Metre (m) | A measure of distance. 1 metre = 100 centimetres. (1 m = 1000 cm). |

Millilitre (ml) | A measure of volume. 10 millimetres = 1 centilitre (10 ml = 1 cl). 1000 millilitres = 1 litre (1000 ml = 1 l). |

Millimetre (mm) | A measure of distance. 10 millimetres = 1 centimetre. (10 mm = 1 cm). |

Modal | Another term for mode |

Mode | The most common value in a list of numbers. If two values are tied then there is two modes. If more than two values are tied then there is no mode. A type ofaverage. |

Month | A time period of either 28, 29, 30 or 31 days. There are 12 months in a year. |

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

N | |

Natural number | A positive integer |

Negative | A value less than zero |

Nonagon | A nine sided polygon. |

Numerator | The top part of a fraction. |

O | |

Obtuse angle | An angle between 90°�and 180°. |

Octagon | An eight sided polygon. |

Odd number | A number that is not a multiple of 2. Odd numbers always end in 1, 3, 5, 7 or 9. |

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. |

P | |

Parallel | Two or more lines which are always the same distance apart. |

Parallelogram | A quadrilateral with two pairs of parallel sides. |

Pentagon | A five sided polygon. |

Perimeter | The distance around a shape. |

Perpendicular | Two or more lines which meet at right angles. |

Pi (Π) | An irrational constant used when calculating the area and circumference of circles. It is approximately equal to 3.14. |

Polygon | A shape made from straight lines. |

Positive number | A number greater than zero. |

Prime | A number which has exactly two factors. The number one 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. |

Q | |

Quadratic equation | An equation where the highest power is two. For example x² + 4x + 6 = 0 is a quadratic equation. |

Quadrilateral | A four sided polygon. |

R | |

Radius | The distance from the centre of a circle to its circumference. The plural of radius is radii. |

Random sampling | A method of choosing people at random for a survey. |

Range | The largest number take away the smallest value in a set of data. |

Rational | A decimal number which ends or is recurring. |

Reciprocal | The reciprocal of any number is 1 divided by the number. E.g. the reciprocal of 3 is 1/3., the reciprocal of 3/4 is 4/3. |

Recurring | A decimal which never ends but repeats all or parts of the sequence of numbers after the decimal point. E.g 0.333333 or 0.141414. |

Reflex angle | An angle greater than 180°. |

Regular | A shape with all sides and angles the same size. |

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°. |

Rotation | To turn a shape using an angle, direction and centre of rotation. |

Round | To reduce the amount of significant figures or decimal places a number has. For example £178 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 list of numbers which follows a pattern. For example 6, 11, 16, 21, ... |

Simplify | To write a sum, expression or ratio in its lowest terms. For example 4:10:6 can be simplified to 2:5:3. |

Solid | A 3D shape. |

Solve | To find the missing value in an equation. |

Speed | How fast an object is moving. Average speed = Total distance divided by time taken. |

Square number | The product when an integer is multiplied by itself. For example, 1, 4, 9, 16, 25, 36, 49, 64, 81, 100. |

Sum | The answer when two or more values are added together. |

Surface area | To total area of all sides on a 3D shape. |

Symmetrical | A shape which has at least one line of symmetry. |

T | |

Tally | A system of counting where every group of four vertical lines is followed by a horizontal line to easily count in steps of five. |

Tangent | A straight line that just touches a point on a curve. A tangent to a circle is perpendicular to the radius which meets the tangent. |

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 a shape from one position to another by sliding in the x-axis followed by the y-axis. |

Trapezium | A quadrilateral with one pair of parallel sides. |

Tree diagram | A method of solving probability questions by listing all the outcomes of an event. Probabilities are calculated by multiplying down the branches. |

Triangle | A three sided polygon. |

Triangular number | A sequence of numbers generated by adding one more than was added to find the previous term. For example, 1, 3, 6, 10, 15, 21, ... |

U | |

Units | A quantity used to describe a measurement. Examples are kilograms, metres and centilitres. |

Upper range | The largest value in a set of data. |

V | |

Value | A numerical amount or quantity. |

Variable | A letter which we don't know the value of. |

Volume | The amount an object can hold. E.g. a bottle of cola has a volume of 2 litres. |

W | |

Week | A time period of 7 days. |

Wide | Used to describe the width of something |

Width | The distance from side to side. E.g. 'The swimming pool is 10 metres wide.' |

X | |

X-Axis | The horizontal axis on a graph. The line going across the page. |

Y | |

Y-Axis | The vertical axis on a graph. The line going from top to bottom. |

Y-Intercept | The value of the y-coordinate when a graph crosses the y-axis. |

Year | A time period of 12 months or 365 days. (366 in a leap year.) |

Z | |

Z-Axis | Represents the depth of an object when working with 3D coordinates. |