Maths Vocab
This is a list of some maths terms with their definition and an example. (More will be added soon)
Term  Definition  Example 

Acute Angle 
An angle that measures less than 90^{o}. 

Area 
The amount of space taken up by a 2D shape or surface. Area is measured in square units for example cm^{2} or m^{2}. 

Array 
A pictorial representation (rows or dots) to help children to understand multiplication and division.  
BIDMAS or BODMAS 
The order to complete mathematical calculations. 

Circumference 
The measurement all the way around the outside edge of a circle. 

Coordinates 
Numbers that give you a position on a grid marked by how far along they are on the x axis and how far up or down they are on the y axis. Always write the x axis value first.  
Denominator 
The bottom number of a fraction that tells you how many parts a shape or amount has been divided equally into.  
Diameter 
The length of a straight line through the centre of a circle from one point on the circumference to another point.  
Divisor 
The number you are dividing by.  
Equilateral Triangle 
A triangle where all sides are the same length and all angles are the same size. 

Exchanging 
Converting from one place value to another  a term used instead of "carrying" in addition and "borrowing" in subtraction.  
Factor 
A whole number which will divide exactly into another number. 

Highest Common Factor (HCF) 
The highest number that two or more whole numbers is divisible by. It could be easier if you listed all the factors of each number.  
Index (Plural: Indices) 
Also know as "power", the index shows how many times the number is used in a multiplication.  
Isosceles Triangle 
Triangles that have 2 sides of equal length and 2 angles of equal size.  
Lowest Common Multiple (LCM) 
The lowest number that is a multiple of two or more numbers.  
Mean 
An average measure that is calculated by adding all the values in a data set together and dividing it by the number of values there are.  
Median  An average measure that shows the middle value when a group of numbers is arranged in order of size.  
Mode 
An average measure that shows the value which appears most frequently in a set of data.  
Multiple 
A number that can be divided by a whole number without remainders. 

Number Bonds 
Pairs of numbers that add up to made a certain number. 

Numerator 
The number on the top of a fraction that tells you how many parts you have.  
Obtuse Angle  An angle that measures more than 90^{o} but less than 180^{o}.  
Partitioning 
Expanding or breaking down a number into the individual values of each digit  this helps with understanding place value. 

Perimeter 
The distance measured around the outside of a 2D shape. 

Place Value 
The value of a digit within a number. 

Prime Number  Numbers that only have two factors which are 1 and the number itself.  
Radius 
The measurement of a straight line from the centre of a circle to any point on the circumference of a circle. 

Range 
An average measure that shows the difference between the highest and the lowest value in a data set.  
Ratio 
A comparison between the amounts of different things.  
Reflex Angle 
An angle that measures more than 180^{o} but less than 360^{o}.  
Right Angle 
An angle that measures exactly 90^{o}. 

Scalene Triangle  A triangle where all the sides are of different lengths and all the angles are different values but one of the angles measures more than 90^{o}.  
Square Number  The value when a number is multiplied by itself.  
x axis 
The horizontal axis on a graph or grid. Remember: "X is across". 

y axis 
The vertical axis on a graph or grid. 
