Lesson 3: The Number System & Roots
Duration of Days: 5
Lesson Objective
Classify numbers as rational or irrational based on their decimal expansion; evaluate perfect square roots and approximate the location of non-perfect square roots to the nearest tenth on a number line without a calculator.
What distinguishes a rational number from an irrational number when looking at its decimal form?
How can perfect squares help us estimate the value of an irrational square root?
How do we determine which tenth an irrational number is closest to without using a calculator?
Rational Number, Irrational Number, Perfect Square, Square Root, Radical Sign, Radicand, Approximations, Non-Perfect Square, Truncate, Repeating Decimal, Terminating Decimal.
8.NS.A.1 (Know that numbers that are not rational are called irrational. Understand informally that every number has a decimal expansion.)`
`8.NS.A.2 (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.)
Purpose: To expand students' mathematical universe beyond rational numbers.
DOK Level: 2 (Skills and Concepts)
Students often mistake a square root for dividing by two.
Provide a reference chart of perfect squares (1 through 225).
Use a physical number line or a visual grid where students can physically place square roots between bounding integer squares to visually confirm their estimates.
Exit Ticket
Quiz