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Lesson 2.1 Use Integers and Rational Numbers. Essential Question: How do you compare positive and negative numbers?. Before we start…. The elevation of several places on Earth is given below. Can you order them from highest to lowest?. South Bend, Indiana + 725.
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Lesson 2.1Use Integers and Rational Numbers Essential Question: How do you compare positive and negative numbers?
Before we start… The elevation of several places on Earth is given below. Can you order them from highest to lowest?
South Bend, Indiana + 725 Valdes Peninsula, Argentina - 131 Fresno, California + 296 Laredo, Texas + 414 Cambridge, Massachusetts + 30 Lake Eyre, South Australia - 52 Dead Sea, Israel-Jordon - 1312
How do you display numbers? • All numbers can be displayed using a number line. • Remember the number line shows every number in order from least to greatest, from negative to positive.
The Sets of Numbers Real Numbers Rational Numbers Integers Whole Numbers
Whole numbers are the counting numbers 0, 1, 2, 3, … • Integers are the numbers -3, -2, -1, 0, 1, 2, … • Positive integers are integers that are greater than 0 • Negative integers are integers that are less than 0 • 0 is neither positive or negative.
What are the rational numbers? • The integers belong to the set of rational numbers. • A rational number can be written as a fraction,
Since a rational number can be written as a fraction, it can also be written as a decimal. • In decimal form, a rational number either terminates or repeats. • Rational numbers belong to the set of real numbers.
Astronomy A star’s color index is a measure of the temperature of the star. The greater the color index, the cooler the star. Order the stars in the table from hottest to coolest.
Astronomy The apparent magnitude of a star is its brightness as observed from Earth. The greater the magnitude, the dimmer the star. Order the stars from brightest to dimmest.
Geography The map shows various locations in Imperial County, California, and their elevations above or below sea level. Order the locations from lowest elevation to highest elevation.
Sports In golf, the goal is to have the least score among all the players. Which golf score, or , is the better score?
What are opposites? • Two numbers that are the same distance from 0 on a number line but are on opposite sides of 0. • 4 and – 4 are opposites because they are both 4 units from 0 and on opposite sides of 0.
What is absolute value? • The absolute value of a number a is the distance between a and 0 on a number line. • The symbol represents the absolute value of a.
What is a conditional statement? • A conditional statement has a hypothesis and a conclusion. • An if-then statement is a form of a conditional statement. • The if part contains the hypothesis. • The then part contains the conclusion.
conditional statement hypothesis conclusion
What do you do with an if-then statement? • In mathematics, if-then statements are either true or false. • An if-then statement is true if the conclusion is always true when the hypothesis is satisfied. • An if-then statement is false if for just one example, counterexample, the conclusion is false when the hypothesis is satisfied.
Tell whether the statement is true or false • If a number is a rational number, then the number is an integer. • If a number is a rational number, then the number is positive.
Tell whether the statement is true or false • If the absolute value of a number is positive, then the number is positive. • If a number is an integer, then the number is either positive or negative.
If a number is a positive integer, then the number is a whole number. • If a number is negative, then its absolute value is negative.
Ticket Out the Door • Order the elements in the table from the lowest boiling-point temperature to highest. Place your name on the paper and place it in the basket.