SECTION 1-1: REAL NUMBERS

AND NUMBER OPERATIONS

Goal: Graph, order and use real numbers

WARM UPSOrder numbers from least to greatest: 1. 0.95, 0.09, 0.192, 0.79

2. 3.55, 3.3, 0.3, 3.13

3. ½, 3/5, ¼, 5/16

REAL NUMBERS

DEFINITIONS Real number line: real numbers are pictured

as points. The numbers increase from left to right.

Origin: the point labeled 0 on a real number line.

Graph (of a number): the point on a number line that corresponds to a real number

Coordinate (of a point): the number that corresponds to a point on a number line

EXAMPLE 1: GRAPH NUMBERS ON A NUMBER LINE

INEQUALITY SYMBOLS A number line can be used to order real

numbers.

The inequality symbols <, <, >, > can be used to compare two numbers

EXAMPLE 2: COMPARE REAL NUMBERS Graph the numbers -1 and -4. The

compare them using the symbol < and >.

EXAMPLE 3: ORDERING TEMPERATURES

CHECKPOINT:

DEFINITIONS: Opposite (additive inverse): of any number a

is –a

Reciprocal (multiplicative inverse): of any nonzero number a is 1/a

EXAMPLE 4: USE PROPERTIES OF REAL NUMBERS Show how you can use the distributive

property to evaluate 5 ● 203.

SUBTRACTION AND DIVISION

Subtraction is defined as adding the opposite.

Division is defined as multiplying by the reciprocal.

EXAMPLE 5: OPERATIONS WITH REAL NUMBERS

A. Find the difference of 4 and -9.

B. Find the quotient of -15 and 1/3 .

CHECKPOINT: A. What is the quotient

of -16 and ½ ? B. What is the product

of -5 and 8?

HOMEWORK:p. 6-8

15-26, 30-38, 42-49, 51-54, 63-77 odd