9th Grade  Project 1 week

Factoring Frenzy: Cracking Quadratics

Jessica A
Updated
CCSS.Math.Content.HSA-REI.B.4
CCSS.Math.Content.HSA-REI.B.4
CCSS.Math.Content.HSN-CN.C.9
CCSS.Math.Content.HSN-CN.C.9
CCSS.Math.Content.HSN-CN.C.7
+ 2 more
1-pager

Purpose

Students investigate multiple ways to solve and factor quadratics, compare when GCF, trinomial factoring, and factoring by grouping are most useful, and build a reasoned answer to which method is most efficient in different cases. Across the week, they test methods on the same equations, including equations with no real factors, to connect factoring, solving, complex solutions, and the idea that quadratic polynomials have two roots. The work leads to a gallery walk board in which each group solves one quadratic three ways and makes a clear mathematical claim about the best method and why it works. Daily math talks help students reflect on efficient strategy use, persistence through mistakes, and how to explain their thinking clearly to others.

Learning goals

Students solve quadratic equations in one variable by comparing multiple factoring approaches on the same expression, including checking for a greatest common factor first, factoring trinomials, and factoring by grouping. They use mathematical reasoning to decide which method is most efficient in a given case and explain why that method works, including cases with real and complex solutions. Students connect factors and roots to justify solutions and build an introductory understanding of why quadratic polynomials have two solutions in the context of the Fundamental Theorem of Algebra. Through daily math talks and a gallery walk presentation board, they communicate claims clearly, listen to others’ strategies, and reflect on how they persisted through mistakes.

Standards
  • [Common Core] CCSS.Math.Content.HSA-REI.B.4 - Solve quadratic equations in one variable.
  • [Common Core] CCSS.Math.Content.HSA-REI.B.4 - Solve quadratic equations in one variable.
  • [Common Core] CCSS.Math.Content.HSN-CN.C.9 - (+) Know the Fundamental Theorem of Algebra; show that it is true for quadratic polynomials.
  • [Common Core] CCSS.Math.Content.HSN-CN.C.9 - (+) Know the Fundamental Theorem of Algebra; show that it is true for quadratic polynomials.
  • [Common Core] CCSS.Math.Content.HSN-CN.C.7 - Solve quadratic equations with real coefficients that have complex solutions.
Competencies
  • Critical Thinking & Problem Solving - Students consider a variety of innovative approaches to address and understand complex questions that are authentic and important to their communities.
  • Effective Communication - Students practice listening to understand, communicating with empathy, and share their learning through exhibiting, presenting and reflecting on their work.

Products

Students create a daily comparison log with worked examples showing how the same quadratic can be approached with GCF first, trinomial factoring, and factoring by grouping, plus a brief note about which method seems most efficient and why. They also contribute to end-of-class math talks by recording one strategy they used to stay focused or persist through mistakes and one method they would choose again. By the end of the week, each group produces a gallery walk presentation board that solves one quadratic three ways, includes a clear claim about the best method and why it works, and uses mathematical reasoning to justify the choice. Groups present their boards to classmates, answer questions about efficiency and correctness, and revise their claims if peer feedback reveals a stronger argument.

Launch

Open with a “Which method wins?” challenge by posting the same quadratic in three forms and having groups test GCF first, trinomial factoring, and factoring by grouping on mini whiteboards, then compare speed, accuracy, and clarity. Ask the essential question and have students make an initial claim about which method seems most efficient and why, using mathematical reasoning from the examples. Include one quadratic that does not factor over the reals so students notice the limits of factoring and raise questions about complex solutions and why quadratics always have two roots. Close with a 2-minute math talk where students share which method felt most efficient today and one strategy they used to stay focused or persist through mistakes.

Exhibition

Host a mini gallery walk in the classroom where groups display their presentation boards showing one quadratic solved three ways, then make a claim about the most efficient method and explain why it works. Invite classmates, another Algebra class, or school staff to circulate, ask questions, and leave feedback on which explanation was clearest and most convincing, including how groups addressed cases with complex solutions. During the exhibition, each group gives a brief 1-minute math talk summarizing when to use GCF first, trinomial factoring, or grouping, and how they decided which method was best. Close with a final reflection circle where students share how their thinking about factoring changed and which strategy helped them persist through mistakes.