1. Sets of numbers
By the end of the lesson you will be able to:
• Identify the different sets of numbers.
• Distinguish between rational and irrational numbers.
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2. Natural numbers
= {1, 2, 3, 4,...}
infinite set
18 ∈
3.5∉
213 ∈
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3. Integer numbers
= {...,­2,­1, 0 , 1 ,2 ,3,...}
whole negative numbers whole positive numbers
zero
Z is for the German "Zahlen"
is an infinite set
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4. Rational numbers
Any number that can be expressed as a fraction
is a rational number. Thus,
fractions ( quotient of whole numbers)
∈
0.25 ∈ terminating (exact) decimals
recurring decimals ­3.2222... ∈
∈
5∈ whole numbers ­40 ∈
is for "quotient"
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5. Irrational numbers
The numbers that are not rational.
(can't be expressed as fractions)
π = 3.1415926535897932384626433832795 (and more...)
is an irrational number
is an irrational number
2,1010010001000010000010000001...
4,12345678910111213142516...
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6. Which of the following sets is infinite?
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7. Answer True or False for each statement:
12 ∈ P 1 ∉ P
5 ∈ P 6 ∈ P
3 ∈ P 0 ∈ P
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8. Which of these represent the empty set?
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9. Which is True?
X ⊂ Y
X ⊂ Z
Z ⊂ Y
Z ⊂ X
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10. Rational or irrational?
rational Pull
irrational Pull
rational Pull
rational Pull
irrational Pull
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11. Ring any of these which are rational when n = 3
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12. At the end of the lesson:
Rational Not rational
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