SETS AND TYPES OF SET

for Grade 7

1. SETS AND SET OPERATIONS LESSON 1

2. Module 1: WHAT IS A SET? A set is a well-defined collection of objects.

3. Column A Column B Collection of: positive integers math books in a library names of students in school provinces in the Philippines Collection of: rich people large animals nice objects bright students

4. In column A, each collection is well-defined because one can identify if an object belongs to the collection or not.

5. In column B, phrases like “ rich people ”, “l arge animals ”, “ nice objects ” & “ bright students ” are not well-defined because these are subjective phrases.

6. Which of the following collections are sets and which are not? Collection of round objects Collection of animals with tails Collection of small boxes

7. WHAT IS AN ELEMENT? An element is an object or item that is contained in the set. Ex: A ={ s , t , u , d , y }

8. symbols Braces { } - are used to enclose the elements of a set. Ex: A = { s, t, u, d, y }

9. symbols means “is an element of”.   Ex: s A   y A   “s is an element of A” “y is an element of A”

10. symbols means “is not an element of”.   Ex: b A   x A   “b is not an element of A” “x is not an element of A”

11. symbols – means empty set - means null set   Ex: Set Y is a set of blue mangoes. Y= or Y=  

12. Module 2: WHAT ARE THE TYPES OF SETS? Consider that sets , , and :    

13. Set is considered as . It is the set containing all the elements of all other sets.    

14. Set and Set are subsets of Set . Therefore,   and    

15. Set is a proper subset of Set because Set has elements that are not in Set . In symbol, .    

16. 2 METHODS OF WRITING SETS ROSTER METHOD- listing of elements. SET-BUILDER METHOD -describing the elements.

17. EXAMPLE ROSTER METHOD SET-BUILDER METHOD A= { x | x is one of the first 5 letters of the English Alphabet } B= { x | x is an odd number less than 20 } C= { x | x is an even number } EXAMPLE ROSTER METHOD SET-BUILDER METHOD A= { x | x is one of the first 5 letters of the English Alphabet } B= { x | x is an odd number less than 20 } C= { x | x is an even number }

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