Reasoning about Equations with Tape Diagrams

Three of These Equations Belong Together

5 min

Problem

Here is a diagram.

Tape diagram, one part marked 6, three parts marked x, total 30.

  1. Which equation matches the diagram?

    1. 6+3x=306+3x=30

    2. 6x+3=306x+3=30

    3. 3x=30+63x=30+6

    4. 30=3x−630=3x-6

  2. Draw a diagram that matches the equation 3(x+6)=303(x+6)=30.

Answer

  1. 6+3x=306+3x=30

  2. Sample response:

    <p>Tape diagram.</p>

Sample Response

  1. 6+3x=306+3x=30

  2. Sample response:

    <p>Tape diagram.</p>

Responding to Student Thinking
More Chancesmore_chances

Response: Students will have more opportunities to understand the mathematical ideas addressed here. There is no need to slow down or add additional work to the next lessons.

Standards
Building Toward
  • 7.EE.4·Use variables to represent quantities in a real-world or mathematical problem, and construct simple equations and inequalities to solve problems by reasoning about the quantities.
  • 7.EE.B.4·Use variables to represent quantities in a real-world or mathematical problem, and construct simple equations and inequalities to solve problems by reasoning about the quantities.