In this lesson, students use a diagram to multiply factors of the form \((a+b)(c+d)\) and gain fluency by using the diagrams in different ways. In the associated Algebra 1 lesson, students factor quadratic expressions of the form \(x^2 - a^2\). Familiarity with using diagrams to find factors can support students with a more concrete method to approach factoring. Students look for and make use of structure (MP7) when they use diagrams to expand and factor partially filled in diagrams.
Lesson overview
- 8.1 Warm-up: Math Talk: Combining the Similar Numbers (5 minutes)
- 8.2 Activity: A Method for Multiplying (15 minutes)
- 8.3 Activity: Find the Missing Pieces (20 minutes)
Learning goals:
- Recognize that two of the terms from the expanded form of quadratics are opposites.
- Use a diagram to multiply expressions.
Learning goals (student facing):
- Let’s explore multiplication strategies.
Standards:
- This lesson builds towards the standard:CCSS.HSA-SSE.A.2MS.A-SSE.2MO.A1.SSE.A.2
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