Term | Description |
whole numbers | Are numbers not written as fractions or decimals and they do not have negative sign e.g. 0,1,2,3,... |
factors | Are numbers that can be multiplied together to get another number. A number can have many factors. E.g. 4x7=28. In this e.g. 4 and 7 are factors of 28. |
composite numbers | Are numbers with more than 2 factors. E.g. 28 is a composite number because it can be obtained by multiplying some of these factors together: 1,2,4,7,28 |
prime numbers | Are numbers that have only 2 factors. The factors are 1 and itself. E.g. 2,3,5,7,… |
integers | Are like “whole numbers”. They can be positive or negative and they include zero. E.g. …-3,-2,-1,0,1,2,3,… |
multiples | Are numbers produced by multiplying 2 integers together. E.g. 15 is a multiple of 3 because 3x5 is 15. |
prime factorisation | Is a way of writing a composite number as a product of prime numbers e.g. 68 is written as
2x2x17 |
square numbers | A square number is produced when a number is multiplied by itself. E.g. 3x3 = 9.
[9 is a square number.] |
square roots | Is represented by √. The square root of 16 is 4 and is written as √16 = 4. In this e.g. we are finding the number which when multiplied by itself gives 16. Square numbers and their square roots are the “opposite” of each other. |
cube | A cube number is produced when a number is multiplied by itself three times. e.g. 3x3x3 = 27. [27 is a cube number.] |
cube root | Is represented by ∛. The cube root of 27 is 3 and is written as ∛27 = 3. In this e.g. we are finding the number which when multiplied by itself three times gives 27. Cube numbers and their cube roots are the “opposite” of each other. |
multiply | Another word for it is "time". The symbol or short form used is "x". |
denote | represent |
product | Is the answer obtained when 2 or more numbers are multiplied together. |
index | Also known as “power”. The index shows the number of times a base (or number) is multiplied by itself. E.g. 1024 can be written as 4⁵ (4 is the base and 5 is the index) |
rational numbers | Are numbers that can be written as fractions. They look like a/b where "a" and "b" are integers and "b" cannot be zero. E.g. 2.5 and 5 are rational numbers because 2.5=5/2 and 5=5/1 |
real numbers | Are numbers that can be written as decimals and can be shown on a number line. |
number line | Is a line used to show the order of real numbers. For any 2 numbers on a horizontal number line, the number on the right will always be bigger. However for any 2 numbers on a vertical number line, the number on top will always be bigger. |
terminating decimals | Are numbers with a fixed number of decimal places e.g. 2.05, -1.369, 0.75(=¾), -1.8(=-1⅘) |
non-terminating decimals | Are numbers with no ending to their decimal places e.g. π , √3 , -0.333..., ⅙ |
repeating decimals | Also known as recurring decimals. They have one or more digits showing repeated pattern after the decimal point e.g. 2.111..., 3.8181..., -4.333...(= -4⅓), 5.1666...(= 5⅙),
-0.666...(=-⅔) |