Lesson Plan

Quadratic Formula

Solving for an unknown


Solve quadratic equations by inspection (e.g., for x2 = 49), taking square roots, completing the square, the quadratic formula and factoring, as appropriate to the initial form of the equation. Recognize when the quadratic formula gives complex solutions and write them as a ± bi for real numbers a and b.


Grades 9 – 12
All Notes
Teacher Notes
Student Notes

1 Hook


Search "Quadratic Formula Song Rockford Christian"


This is a common song that recites the Quadratic Form, so the students can remember the complex formula.

2 Direct Instruction



Khan Academy is a great way a substitute teacher can present the lesson to the class.  This link leads to a short lesson with concrete examples.

3 Guided Practice


In groups of two or three students can use this app to practice the Quadratic Formula.  The teacher can still guide the students through the process and clarify any questions.

4 Independent Practice

Free to try, Paid

5 Wrap-Up

TenMarks Math
Free to try, Paid


Homework where the teacher can see relevant data and the students can use a finite number of hints.