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