Section 1.1 ­ Real Numbers and Number Operations A.notebook

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July 29, 2009

Section 1.1 ­ Real Numbers and Number Operations

Subsets of Real Number

Whole Numbers: 0, 1, 2, 3 …

Integers: ­3, ­2, ­1, 0, 1, 2, 3…

Rational Numbers: numbers that can be expressed as a ratio, like ¾, ½, ­5/8

Irrational Numbers: numbers that cannot be expressed as a ratio, like π or √2

Section 1.1 ­ Real Numbers and Number Operations A.notebook

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July 29, 2009

Using Real Numbers

Example: Graph the numbers √2, 2.7, and ­4/3 on a number line and order them from least to greatest.

­1 0­2­3­4­5 1 2 3 4 5

Properties of Numbers

Let a, b, and c be real numbers

Commutative: a + b = b + a additionab = ba multiplication

Associative: (a + b) + c = a + (b + c) addition(ab)c = a(bc) multiplication

Distributive: a(b + c) = ab + ac

Section 1.1 ­ Real Numbers and Number Operations A.notebook

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July 29, 2009

Properties of Numbers

Let a, b, and c be real numbers

Identity: a + 0 = a additiona ∙ 1 = a multiplication

Inverse: a + (­a) = 0 addition a ∙ 1/a = 1; a ≠ 0 multiplication

Homework Section 1.1 Worksheet #2 ­ 28 even