Classify numbers

1. Tell whether each of the following numbers is a whole number, an integer, or a rational number:5, 0.6, –2 , and –24. 2 3 Number Whole number? Integer? Rational number? 2 5 Yes Yes Yes 3 0.6 No No Yes No No Yes –2 –24 No Yes Yes EXAMPLE 2 Classify numbers

2. EXAMPLE 3 Order rational 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. SOLUTION Begin by graphing the numbers on a number line.

3. ANSWER From hottest to coolest, the stars are Shaula, Rigel, Denebola, and Arneb. EXAMPLE 3 Order rational numbers Read the numbers from left to right:– 0.22, – 0.03, 0.09, 0.21.

4. Number Whole number? Integer? Rational number? 3 Yes Yes Yes –1.2 No No Yes –2 No Yes Yes 0 Yes Yes Yes for Examples 2 and 3 GUIDED PRACTICE Tell whether each number in the list is a whole number, an integer, or a rational number.Then order the numbers from least to greatest. 4. 3, –1.2, –2,0

5. ANSWER –2, –1.2, 0, 3 (Ordered the numbers from least to greatest). for Examples 2 and 3 GUIDED PRACTICE

6. Number Whole number? Integer? Rational number? 5. 4.5, – , – 2.1, 0.5 4.5 No No Yes 3 No No Yes – 3 3 4 4 4 No No Yes –2 .1 0.5 No No Yes ANSWER – 2.1, – , 0.5 , – 2.1.(Order the numbers from least to greatest). for Examples 2 and 3 GUIDED PRACTICE

7. ANSWER Number Whole number? Integer? Rational number? –2.8, –1.5, – 0.31, 3.6 (Ordered the numbers from least to greatest). 3.6 No No Yes –1.5 No No Yes –0.31 No No Yes –2.8 No No Yes for Examples 2 and 3 GUIDED PRACTICE 6. 3.6, –1.5, –0.31, – 2.8

8. 2 7. , 1.75, – , 0 3 Number Whole number? Integer? Rational number? 1 No No Yes 6 1.75 No No Yes 1 1 2 6 6 No No Yes – 3 0 Yes Yes Yes ANSWER 2 – , 0 , , 1.75. (Order the numbers from leastto greatest). 3 for Examples 2 and 3 GUIDED PRACTICE