enVision Mathematics Topic 1
8th Grade; August – September (5 weeks); 1st Quarter
enVision Mathematics Topic 1
8th Grade; August – September (5 weeks); 1st Quarter
Topic Title(s):
Real Numbers
Prepared Graduates:
MP5. Use appropriate tools strategically.
MP7. Look for and make use of structure.
MP8. Look for and express regularity in repeated reasoning.
Standard(s):
1. Number and Quantity
2. Algebra and Functions
The highlighted evidence outcomes are the priority for all students, serving as the essential concepts and skills. It is recommended that the remaining evidence outcomes listed be addressed as time allows, representing the full breadth of the curriculum.
Students Can (Evidence Outcomes):
8.NS.A. The Number System: Know that there are numbers that are not rational, and approximate them by rational numbers.
Demonstrate informally that every number has a decimal expansion; for rational numbers show that the decimal expansion repeats eventually, and convert a decimal expansion which repeats eventually into a rational number. Define irrational numbers as numbers that are not rational. (CCSS: 8.NS.A.1)
Use rational approximations of irrational numbers to compare the size of irrational numbers, locate them approximately on a number line diagram, and estimate the value of expressions (e.g., 𝜋2). For example, by truncating the decimal expansion of √2, show that √2 is between 1 and 2, then between 1.4 and 1.5, and explain how to continue on to get better approximations. (CCSS: 8.NS.A.2)
8.EE.A. Expressions & Equations: Work with radicals and integer exponents.
Know and apply the properties of integer exponents to generate equivalent numerical expressions. For example, 32 × 3−5 = 3−3 = 1/33 = 1/27. (CCSS: 8.EE.A.1)
Use square root and cube root symbols to represent solutions to equations of the form x2 = p and x3 = p, where p is a positive rational number. Evaluate square roots of small perfect squares (up to 100) and cube roots of small perfect cubes (up to 64). Know that √2 is irrational. (CCSS: 8.EE.A.2)
Use numbers expressed in the form of a single digit times an integer power of 10 to estimate very large or very small quantities, and to express how many times as much one is than the other. For example, estimate the population of the United States as 3 times 108 and the population of the world as 7 times 109, and determine that the world population is more than 20 times larger. (CCSS: 8.EE.A.3)
Perform operations with numbers expressed in scientific notation, including problems where both decimal and scientific notation are used. Use scientific notation and choose units of appropriate size for measurements of very large or very small quantities (e.g., use millimeters per year for seafloor spreading). Interpret scientific notation that has been generated by technology. (CCSS: 8.EE.A.4)
Investigate rational and irrational numbers and their relative approximate positions on a number line. (Entrepreneurial Skills: Inquiry/Analysis)
Use technology to look for repetition in decimal expansions and use number lines to order and compare irrational numbers relative to rational numbers. (MP5)
Apply understanding of rational and irrational numbers to describe and work within the structure of the real number system effectively and efficiently. (MP7)
Recognize repetition in decimal expansions of rational numbers and recognize when a decimal expansion cannot be represented by a rational number. (MP8)
Reason about unusually large or small quantities. (Entrepreneurial Skills: Inquiry/Analysis)
Use calculators or computers to compute with and approximate radicals and roots, and understand how such tools represent scientific notation. (MP5)
Explore the structure of numerical expressions with integer exponents to generate equivalent expressions. (MP7)
Look for how positive integer exponents are equivalent to repeated multiplication by the base and how negative integer exponents are equivalent to repeated division by the base. (MP8)
Inquiry Questions
How many irrational numbers exist?
Why is there no real number closest to zero?
Can you accurately plot an irrational number on the number line? How do you know?
How is performing operations on numbers in scientific notation similar to or different from performing operations on numbers in standard notation?
Why does a positive number raised to a negative exponent not equal a negative number?
Coherence Connections
This expectation (8.NS.A) supports the major work of the grade.
This expectation (8.EE.A) represents major work of the grade.
In Grade 5, students use whole-number exponents to denote powers of ten. In Grades 6 and 7, they work with algebraic and numerical expressions containing whole-number exponents.
In Grade 7, students apply and extend previous understandings of operations with fractions to add, subtract, multiply, and divide rational numbers.
In Grade 8, this expectation supports working with radicals and integer exponents. This concludes the introduction of all numbers that comprise the real number system.
In Grade 8, this expectation connects with knowing that there are numbers that are not rational and approximating them by rational numbers, understanding and applying the Pythagorean Theorem, and solving real-world and mathematical problems involving volume of cylinders, cones, and spheres.
In high school, students use properties of rational and irrational numbers, work with rational exponents, and extend their understanding of number systems to include complex numbers.
Academic Vocabulary & Language Expectations:
Irrational number, perfect square, square root, cube root, perfect cube, Power of Products Property, Product of Powers Property, Quotient of Powers Property, Negative Exponent Property, Zero Exponent Property, scientific notation
Assessments:
Instructional Resources & Notes:
enVision Mathematics Topic 1
Let's Investigate! Tasks
Let's Investigate! Distinctive Decimals (TE) (relates to Lesson 1-2)
Let's Investigate! How Many More from 0 to 4? (TE) (relates to Lesson 1-3)
Let's Investigate! Massive Moments of Magnitude (TE) (relates to Lesson 1-8)
Tier 1 Intervention & Supports (i-Ready Tools for Instruction):
Tier 1 Intervention: Approximate and Order Irrational Numbers, Exponent Properties, Negative Exponents, Evaluate Expressions with Integer Exponents, Solve Equations Using Square and Cube Roots, Compare and Estimate with Powers of 10
Coherence Map/Concept Progressions: 8.NS.A.1, 8.NS.A.2, 8.EE.A.1, 8.EE.A.2, 8.EE.A.4
enVision Mathematics 6-8 & Number Worlds Connections (for SVVSD Special Education teachers only)