A set is a collection of things. These things can be anything from numbers and letters to shapes or even other sets themselves!
Each item in a set is called an element. Sets are written with curly braces {} and the elements are listed inside, separated by commas. For example, the set of primary colors can be written as {red, yellow, blue}.
Order does not matter!
The order you list the elements in a set doesn't matter. {red, yellow, blue} is the same set as {blue, yellow, red}
Elements must be unique within a set. You can't have the same element listed twice. For example, {1, 2, 2} is not a valid set because the number 2 appears twice.
There are a number of standard symbols that represent different sets of numbers.
| Number Sets | |
|---|---|
| Natural | |
| Whole | |
| Integers | |
| Rational | |
| Irrational (Complement of ) | |
| Real () | |
| Empty Set | |
For more symbols and operations see: Set Symbols Reference