8th GradeSquare rootsabout 3 minCCSS 8.NS.A.1Know that numbers that are not rational are called irrational. Understand 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.CCSS 8.NS.A.2Use 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., π^2).CCSS 8.EE.A.2Use square root and cube root symbols to represent solutions to equations of the form x^2 = p and x^3 = p, where p is a positive rational number. Evaluate square roots of small perfect squares and cube roots of small perfect cubes. Know that √2 is irrational.+0
Fold a sheet in half, double a square tile, and swing a diagonal down.
Lesson Plan
Explore square roots and irrational numbers, and estimate the square root of 2 with rational approximations.
Big idea: Pause. Ask a student to say the idea in their own words.
Question: Ask what students spot and what they are curious about. Read “Which sheet do we fold first?” aloud. Have each student guess and say why.
Question: Read “How much longer for twice the area?” aloud. Have partners explain their guesses to each other.
Question: Read “Where does it land?” aloud. Ask a student who guessed differently to explain.
Big idea: Pause. Have partners explain the idea to each other.
Big idea: Pause. Ask how this idea connects to the last one.
Your turn: Have students try their own. Ask them to predict before they test.
How to run it
Whole classPut the lesson on the board. At each choice the class votes, then you select the winner.
SoloShare the link, QR code, or post to Google Classroom. Each student gets to take their own path.
