Lesson 5: 1.5 Combining Like Terms
Duration of Days: 10
Lesson Objective
Students will simplify algebraic expressions by grouping identical variables and constants.
Why can we combine 3x and 2x, but we cannot combine 3x and 2?
Like Terms
Coefficient
Constant
Combine
CCSS.MATH.CONTENT.8.EE.A.1
Description: Students use physical algebra tiles (rectangles for 'x', squares for constants). They physically sort a mixed pile into identical shapes, count them, and write the simplified algebraic expression (ex. 3 rectangles + 4 squares = 3x + 4).
Purpose: To visually prove that unlike quantities cannot be combined, preventing the common barrier of adding coefficients to constants.
DOK Level: DOK 2 (Skill/Concept) - Classifying, organizing, and distinguishing between different types of mathematical terms.
Color-coding terms on paper (circle all x's in blue, all constants in red with their signs).
Adapted Quiz: 5 questions. Students are provided with a visual bank of shapes next to the expression. They must write the final simplified expression. A word bank of possible answers is provided at the bottom.
Algebra tiles or cut-out paper shapes, colored pencils, sorting trays.