A set is a collection of elements with defined properties. Numerical sets describe fundamental element "number". Different sets are linked and smaller sets are included in larger ones
A set of numbers allows different types of numbers to be placed in various categories. The classical representation of sets is N ⊆ Z ⊆ Q ⊆ R ⊆ C. The symbols ∈, ∊, ∉, and ⊂ indicate membership in or exclusion from sets
Number sets are groups of numbers sharing the same definition. Students learn about number sets from kindergarten to high school. Elementary school focuses on rational numbers and their subsets. Later grades include irrational numbers and real numbers