Math 3 Honors: Unit 2
Name: _____________________________________
Real Number Classification
N- Natural Numbers
N
-3
W- Whole Numbers
Z- Integers
Q- Rational Numbers
3
0
1
3
10
π
7.45
i
I- Irrational Numbers
R- Real Numbers
W
Z
Q
I
R
SET (or GROUP) NOTATION { }: an unordered list of elements in group or set
Special Notation:
 = Empty Set = { } represents a set of no elements.
Example: Class A has Anna, Beth, Chris, David, Eli, and Ferris. Class B has
Amanda, Beth, Carter, David, Eleanor, and Ferris.
INTERESECTION ∩: The intersection of groups/sets is the list of all common
elements to the groups.
Generally the intersection represents a smaller group of elements than the original groups.
Example: What is the intersection of class A and class B (A∩ B)?
UNION : The union of groups/sets is the list of all elements from the groups.
Generally the intersection represents a larger group of elements than the original groups.
Example: What is the union of class A and class B (AB)?
VENN DIAGRAM: Complete the Venn Diagram for the above example and determine
who it relates to set/group notation.
CLASS A
CLASS B
PRACTICE SET NOTATION PROBLEMS:
1)
A = {1, 2, 3, 5, 7}
B = {0, 2, 4, 6, 8}
2)
B = {Boys}
G = {Girls}
3) A = {Apple, Banana, Grape, Kiwi}
B = {Apple, Coconut, Egg, Kiwi}
What is A∩B?
What is BG?
What is A∩B?
What is AB?
What is G∩B?
What is AB?
5) Rational ∩ Integers =
7) Natural  Whole =
6) Rational  Irrational =
8) Irrational ∩ Rational =
Determine if each statement is Sometimes, Always, or Never True:
 Give an example of True and False for Sometimes answers.
 Be prepared to defend your answer.
1) The sum of a rational and irrational is irrational.
2) The sum of two rational numbers is rational.
3) The sum of two irrationals is irrational.
4) The product of a rational and irrational is irrational.
5) The product of irrational and irrational is rational.
6) The product of rational and rational is irrational.