Learning goals: Teacher Facing Calculate an approximate value of a square root to the nearest tenth, and represent the square root as a point on the number line. Determine the exact length of a line segment on a coordinate grid and express the length (in writing) using square root notation. Explain (orally) how to verify that a value is a close approximation of a square root. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 8.8 Pythagorean Theorem and Irrational Numbers, Grade 8.