Grade 7 math

• Set


  A group or collection of objects
• Set


  • Named using capital letters
  • Each object in a set is called a member or an element
• Types of sets


  • Integers
  • Whole numbers
  • Counting numbers
  • Even numbers
  • Odd numbers
  • Prime numbers
  • Composite numbers
  • Perfect squares
  • Multiples
  • Factors
• Element


  An object that is part of a set
• Not an element


  Represented by a slash through the element symbol
• Well-defined set


  A set where the membership criteria is clear and unambiguous
• Not well-defined set


  A set where the membership criteria is unclear or subjective
• Empty set/Null set


  A set with no elements
• Cardinality


  The number of elements in a set
• Cardinality examples


  • Set of primary colors has 3 elements
  • Set of school days in a week has 5 elements
  • Set of days in a week starting with A has 0 elements (empty set)
• The cardinality of an empty set is 0