Students can use the Spectrum Math Grade 8 Answer Key Chapter 2 Lesson 2.7 Comparing and Ordering Irrational Numbers as a quick guide to resolve any of their doubts.
Spectrum Math Grade 8 Chapter 2 Lesson 2.7 Comparing and Ordering Irrational Numbers Answers Key
Rational and irrational numbers can be compared by approximating their value and placing them along a number line.
Place these numbers on a number line: \(\sqrt{5}\), 2.5, \(\sqrt{3}\)
Put the values below in order from least to greatest along a number line.
Question 1.
π2, 10, \(\sqrt{75}\)
Answer:
Rational and irrational numbers can be compared by approximating their value and placing them along a number line.
Question 2.
\(\sqrt{7}\), \(\frac{\sqrt{7}}{2}\), 2
Answer:
Rational and irrational numbers can be compared by approximating their value and placing them along a number line.
Question 3.
\(\sqrt{10}\), 3.5, 22
Answer:
Rational and irrational numbers can be compared by approximating their value and placing them along a number line.
Question 4.
4, \(\sqrt{15}\), 5.2
Answer:
Rational and irrational numbers can be compared by approximating their value and placing them along a number line.
Question 5.
\(\frac{1}{3}\), \(\sqrt{1}\), 0.45
Answer:
Rational and irrational numbers can be compared by approximating their value and placing them along a number line.
Question 6.
\(\sqrt{72}\), 9, 82
Answer:
Rational and irrational numbers can be compared by approximating their value and placing them along a number line.
Expressions and equations containing irrational numbers can be approximated by testing values.
Compare using <, >, or =.
\(\sqrt{3}\) + 5 ____ 3 + \(\sqrt{5}\)
\(\sqrt{3}\) is between 1 and 2, so use 1.5.
\(\sqrt{5}\) is between 2 and 3, so use 2.5.
(1.5) + 5 ____ 3 + (2.5)
6.5 > 5.5
Approximate the value of each expression and then compare using <, >, or =.
Question 1.
a. \(\sqrt{10}\) + 2 _____ 10 + \(\sqrt{2}\)
Approximation: ____________
Answer: \(\sqrt{10}\) + 2 < 10 + \(\sqrt{2}\)
\(\sqrt{10}\) + 2 _____ 10 + \(\sqrt{2}\)
\(\sqrt{10}\) is between 3 and 4, so use 3.5.
\(\sqrt{2}\) is between 1 and 2, so use 1.5.
3.5 + 2 _________ 10 + 1.5
5.5 < 11.5
b. 4 + \(\sqrt{2}\) _____ \(\sqrt{4}\) + 2
Approximation: ____________
Answer: 4 + \(\sqrt{2}\) > \(\sqrt{4}\) + 2
4 + \(\sqrt{2}\) _____ \(\sqrt{4}\) + 2
\(\sqrt{2}\) is between 1 and 2, so use 1.5.
\(\sqrt{4}\) is 2.
4 + 1.5 _____2 + 2
5.5 > 4
Question 2.
a. 12 + \(\sqrt{6}\) _____ \(\sqrt{12}\) + 6
Approximation: ____________
Answer: 12 + \(\sqrt{6}\) < \(\sqrt{12}\) + 6
12 + \(\sqrt{6}\) _____ \(\sqrt{12}\) + 6
\(\sqrt{6}\) is between 2 and 3, so use 2.5.
\(\sqrt{12}\) is between 3 and 4, so use 3.5.
12 +2.5 _________ 3.5+6
14.5 < 9.5
b. \(\sqrt[3]{8}\) + 6 _____ 8 + \(\sqrt[3]{6}\)
Approximation: ____________
Answer: \(\sqrt[3]{8}\) + 6 < 8 + \(\sqrt[3]{6}\)
\(\sqrt[3]{8}\) + 6 _____ 8 + \(\sqrt[3]{6}\)
\(\sqrt[3]{8}\) is 2.
\(\sqrt[3]{6}\) is 1 and 2, so use 1.5.
2 + 6 ______ 8+1.5
8 < 9.5
Question 3.
a. 15 + \(\sqrt{12}\) _____ \(\sqrt{15}\) + 12
Approximation: ____________
Answer: 15 + \(\sqrt{12}\) > \(\sqrt{15}\) + 12
15 + \(\sqrt{12}\) _____ \(\sqrt{15}\) + 12
\(\sqrt{12}\) is between 3 and 4, so use 3.5.
\(\sqrt{15}\) is between 3 and 4, so use 3.5.
15 + 3.5 ________ 3.5+12
18.5 > 15.5
b. \(\sqrt{7}\) + 3 _____ 7 + \(\sqrt{3}\)
Approximation: ____________
Answer: \(\sqrt{7}\) + 3 < 7 + \(\sqrt{3}\)
\(\sqrt{7}\) + 3 _____ 7 + \(\sqrt{3}\)
\(\sqrt{7}\) is between 2 and 3, so use 2.5.
\(\sqrt{3}\) is between 1 and 2, so use 1.5.
2.5 + 3 ________ 7+1.5
5.5 < 8.5
Question 4.
a. 4 + \(\sqrt[3]{7}\) _____ \(\sqrt[3]{4}\) + 7
Approximation: ____________
Answer: 4 + \(\sqrt[3]{7}\) < \(\sqrt[3]{4}\) + 7
4 + \(\sqrt[3]{7}\) _____ \(\sqrt[3]{4}\) + 7
\(\sqrt[3]{7}\) is between 1 and 2, so use 1.5.
\(\sqrt[3]{4}\) is between 1 and 2, so use 1.5.
4 + 1.5 ________ 1.5 + 7
5.5 < 8.5
b. \(\sqrt{3}\) + 5 _____ 3 + \(\sqrt{5}\)
Approximation: ____________
Answer: \(\sqrt{3}\) + 5 > 3 + \(\sqrt{5}\)
\(\sqrt{3}\) + 5 _____ 3 + \(\sqrt{5}\)
\(\sqrt{3}\) is between 1 and 2, so use 1.5.
\(\sqrt{5}\) is between 2 and 3, so use 2.5.
1.5 + 5 ________ 3 + 2.5
6.5 > 5.5