- Topic of the unit
Linear Equations and Systems (Unit 2)
- Grade level
9th Grade (High School)
- Name of the two lessons
- Equivalent Equations (Lesson 6)
- Explaining Steps for Rewriting Equations (Lesson 7)
- The New York State content and practice learning standards that need to be met in each lesson.
- Equivalent Equations (Lesson 6)
- 6.EE.A.4: Identify when two expressions are equivalent (i.e., when the two expressions name the same number regardless of which value is substituted into them). For example, the expressions y+y+y and 3y are equivalent because they name the same number regardless of which number y stands for.
- HSA-CED.A.2: Create equations in two or more variables to represent relationships between quantities; graph equations on coordinate axes with labels and scales.
- Â HSA-REI.A.1: Explain each step in solving a simple equation as following from the equality of numbers asserted at the previous step, starting from the assumption that the original equation has a solution. Construct a viable argument to justify a solution method.
- Â HSA-SSE.A.1: Interpret expressions that represent a quantity in terms of its context.
- HSA-REI.A: Understand solving equations as a process of reasoning and explain the reasoning.
- Explaining Steps for Rewriting Equations (Lesson 7)
- HSA-REI.A: Understand solving equations as a process of reasoning and explain the reasoning.
- Â HSA-REI.A.1: Explain each step in solving a simple equation as following from the equality of numbers asserted at the previous step, starting from the assumption that the original equation has a solution. Construct a viable argument to justify a solution method.
- Equivalent Equations (Lesson 6)
- Identify the Standards for Mathematical Practice to be addressed.
- Equivalent Equations (Lesson 6)
- HSA-CED.A.2: Create equations in two or more variables to represent relationships between quantities; graph equations on coordinate axes with labels and scales.
- Â HSA-REI.A.1: Explain each step in solving a simple equation as following from the equality of numbers asserted at the previous step, starting from the assumption that the original equation has a solution. Construct a viable argument to justify a solution method.
- Â HSA-SSE.A.1: Interpret expressions that represent a quantity in terms of its context.
- MP2: Students learned that equivalent equations are equations that have exactly the same solutions.
- Explaining Steps for Rewriting Equations (Lesson 7)
- HSA-REI.A: Understand solving equations as a process of reasoning and explain the reasoning.
- Â HSA-REI.A.1: Explain each step in solving a simple equation as following from the equality of numbers asserted at the previous step, starting from the assumption that the original equation has a solution. Construct a viable argument to justify a solution method.
- MP3: Further develop the concept of equivalent equations. Students think about and explain how they know that the equations produced using acceptable transformations are indeed equivalent.
- Equivalent Equations (Lesson 6)
- Identify 3-4 learning objectives for the unit that align with the chosen standards.
- Students can understand the study of systems of linear equations, their solutions, and their graphical representation.
- Students can understand and recognize the graphical representation of a linear equation with two variables as the set of all ordered pairs that satisfy the equation.
- Students can understand how to write equations using numbers and variables to describe relationships and constraints.
- Students can understand how to use structure or rearrange equations to determine the slope and y-intercept of the graph of a linear equation.
- Identify the new vocabulary to be addressed.
- Equivalent Equations (Lesson 6)
- equivalent equations:Equivalent equations are equations that have the exact same solutions.
- Explaining Steps for Rewriting Equations (Lesson 7)
- Elimination:Elimination is a method of solving a system of two equations in two variables. A multiple of one equation is added to or subtracted from another to get an equation with only one of the variables. (The other variable is eliminated.)
- Equivalent Equations (Lesson 6)
- Present a list of activities (with timing) for each lesson, and questions that you, the teacher, will ask as part of the activities. 

- Equivalent Equations (Lesson 6)
- Warm-up (5 mins): Two Expressions
- “Were you surprised that these expressions have the same result for different values of n?” (No, because using distribution in the n denominator results in the same values, so the other parts with the may do the same thing.)
- “If (or when) you tried using other values of n, what did you find?” (They were the same for all the different kinds of numbers we tried.)
- “Do you think that the two expressions will have the same value no matter what value of n is used? How do you know?” (Yes, because the distributive property shows that the numerators are equivalent and so are the denominators.)
- Activity (15 mins): Much Ado about Ages
- “Consider the equations you wrote for each situation. Are they all equivalent? Why or why not?”
- “What do you think it means for two equations to be equivalent?”
- Activity (15 mins): What’s Acceptable?
- Why do these operations result in equations with the same solutions?
- Cool-down (5mins): Box of Beans and Rice
- Warm-up (5 mins): Two Expressions
- Explaining Steps for Rewriting Equations (Lesson 7)
- Warm-up (5 mins): Math Talk: Could It Be Zero?
- Give students quiet time to think, and ask them to give a signal when they have an answer and a strategy.
- Invite students to share their strategies, and record and display their responses for all to see.
- Activity (15 mins): Explaining Acceptable Moves
- Explain why certain actions are effective methods for writing equivalent equations?
- Activity (15 mins): It Doesn’t Work!
- Why do performing acceptable operations on these equations always result in equivalent equations with the same solutions?
- Cool-down (5mins): If This, Then That
- Warm-up (5 mins): Math Talk: Could It Be Zero?
- Equivalent Equations (Lesson 6)
- Design both formal and informal assessments to evaluate whether the learning objectives have been achieved.Â
- Equivalent Equations (Lesson 6)
- A cardboard box, which weighs 0.6 pounds when empty, is filled with 15 bags of beans and a 4-pound bag of rice. The total weight of the box and the contents inside it is 25.6 pounds. One way to represent this situation is with the equation 0.6+15b+4=25.6.
- Equivalent Equations (Lesson 6)
In this situation, what does the solution to the equation represent?
- Explaining Steps for Rewriting Equations (Lesson 7)
- The equation 4(x-2)=100 is a true equation for a particular value of x. Explain why 2(x-2)=50 is also true for the same value of x.
- References
- https://accessim.org/9-12-aga/algebra-1/unit-2/section-b/lesson-6/preparation?a=teacher
- https://accessim.org/9-12-aga/algebra-1/unit-2/section-b/lesson-6?a=teacher
- https://accessim.org/9-12-aga/algebra-1/unit-2/section-b/lesson-7/preparation?a=teacher
- https://accessim.org/9-12-aga/algebra-1/unit-2/section-b/lesson-7?a=teacher
- https://accessim.org/6-8/grade-6/course-guide/standards-reference?a=teacher#6eea4
- https://accessim.org/9-12-aga/algebra-1/course-guide/standards-reference?a=teacher#hsa-ceda2
- https://accessim.org/9-12-aga/algebra-1/course-guide/standards-reference?a=teacher#hsa-reia
- https://accessim.org/9-12-aga/algebra-1/course-guide/standards-reference?a=teacher#hsa-reia1
- https://accessim.org/9-12-aga/algebra-1/course-guide/standards-reference?a=teacher#hsa-ssea1
- https://accessim.org/9-12-aga/algebra-1/course-guide/standards-reference?a=teacher#hsa-reia