Glendale Unified School District
Math Curriculum
Math 8 Parent Information
Unit 3: Rational and Irrational Numbers
What Your Child Will Learn:
In Unit 3, students will recognize perfect squares and cubes, and find square roots and cube
roots of perfect squares and cubes. Students will define irrational numbers a numbers that cannot be
expressed as a fraction, therefore neither terminate nor repeat in their decimal forms. Students will
also convert repeating decimals to their fraction equivalents.
MORE SPECIFICALLY, CHILDREN WILL LEARN HOW TO:
• Recognize perfect squares and cubes, understanding that non-perfect squares and non-perfect
cubes are irrational.
• Recognize that squaring a number and taking the square root of a number are inverse operations;
likewise, cubing a number and taking the cube root are inverse operations.
• Distinguish between rational and irrational numbers, recognizing that any number that can be
expressed as a fraction is a rational number.
• Convert repeating decimals into their fraction equivalent using patterns or algebraic reasoning
• Approximate irrational numbers in order to locate rational and irrational numbers on the number
line.
• Compare and order irrational numbers.
Standards: 8.EE.1, 8.NS.1, 8.EE.2
For more information on the strategies, standards and explanations, visit the Grade 8 Chapter of the Mathematics
Framework for California Public Schools: Kindergarten through Grade Twelve at:
http://www.cde.ca.gov/ci/ma/cf/documents/mathfwgrade8jl.pdf
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Sample Problems:
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These problem examples are from the Framework.
Learning Link:
Additional practice problems and videos can be found on KhanAcademy.org. Sign up for a free
account at KhanAcademy.org
Cube roots and square roots of perfect squares
https://www.khanacademy.org/math/algebra-basics/core-algebra-foundations/square-roots-forcollege/e/square_roots
https://www.khanacademy.org/math/pre-algebra/exponents-radicals/cube-root-tutorial/e/cube_roots
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Rational and irrational numbers
https://www.khanacademy.org/commoncore/grade-8-NS#8.NS.A.1
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To see an electronic copy of this parent letter, with “clickable” links, please go to the Common Core pages at
www.GUSD.net. Follow the links to mathematics, Grade 8. Scroll to the bottom of the page and click on Unit 3.