Maths Glossary

mathematical words you need to know


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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

A
Acute angle An angle less than 90º.
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 35m2.
Average A value to best represent a set of data. There are three type of average - the mean, the median and the mode.
B
BIDMAS A way of remembering the order in which operations are carried out. It stands for
Brackets - Indices - Division - Multiplication - Addition - Subtraction.
C
Centimetre (cm) A measure of distance. 1 centimetre = 10 millimetres. (1 cm = 10 mm).
100 centimetres = 1 metre. (100 cm = 1 m).
Centilitre (cl) A measure of volume. 100 centilitres = 1 litre (100 cl = 1 l).
1 centilitre = 10 millilitres (1 cl = 10 ml).
Circumference The perimeter of a circle.
Constant A letter or symbol whose value always stays the same. The constant π is a common example.
Cross section The end section created when you slice a 3D shape along it's length.
D
Day A time period of 24 hours. There are 7 days in a week.
Denominator The bottom part of a fraction.
Diameter The distance across a circle which passes through the centre.
E
Equation Two expressions which have the same value, separated by an "=" sign. E.g. 3y = 9 + y
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.
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.
Frequency How many times something happens. Another word for "total".
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.
Hypotenuse The longest side on a right angled triangle.
I
Integer A whole number.
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 litres = 1000 millilitres (1l = 1000 ml).
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).
Millimetre (mm) A measure of distance. 10 millimetres = 1 centimetre. (10 mm = 1 cm).
Millilitre (ml) A measure of volume. 10 millimetres = 1 centilitre (10 ml = 1 cl).
1000 millilitres = 1 litre (1000 ml = 1 l).
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 of average.
Modal Another term for mode
Month A time period of either 28, 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 The value less than zero.
Numerator The top part of a fraction.
O
Obtuse angle An angle between 90º and 180º.
Octagon An eight sided polygon.
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.
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.
Prism A 3D shape with the same cross section all along its length.
Product The answer when two values are multiplied together.
Q
Quadrilateral A four sided polygon.
R
Radius
The distance from the centre of a circle to its circumference. The plural of radius is radii.
Range
The largest number take away the smallest value in a set of data.
Rational A decimal number which ends or is recurring.
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 180º.
Right angle An angle of 90º.
S
Sum The answer when two or more values are added together.
T
Term A number, variable or combination of both which forms part of an expression.
Triangle A three sided polygon.
U
Units A quantity used to describe a measurement. Examples are kilograms, metres and centilitres.
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