ALEX Lesson Plan


Is My Vari"able" to Stand?

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  This lesson provided by:  
Author:Summer Johnson
System: Roanoke City
School: Roanoke City Board Of Education
Author:De Lambert
System: Roanoke City
School: Handley Middle School
  General Lesson Information  
Lesson Plan ID: 33085


Is My Vari"able" to Stand?


This cross-curricular lesson is designed to require students to apply algebra to a real world, natural disaster situation. Students will be asked to design a treehouse including a ladder. Students will set up an algebraic equation and solve for the variable. Will their treehouse be able to withstand a "jelloquake"? Students will test the strength of their treehouse and ladder in science class.

This is a College- and Career-Ready Standards showcase lesson plan.

 Associated Standards and Objectives 
Content Standard(s):
SC (6)
2. Describe factors that cause changes to Earth's surface over time.
Examples: earthquakes, volcanoes, weathering, erosion, glacial erosion or scouring, deposition, water flow, tornadoes, hurricanes, farming and conservation, mining and reclamation, deforestation and reforestation, waste disposal, global climate changes, greenhouse gases
  • Comparing constructive and destructive natural processes and their effects on land formations
  • Examples:
    constructive—volcanic and mountain-building processes;
    destructive—erosion by wind, water, and ice
  • Distinguishing rock strata by geologic composition
  • Examples: predicting relative age of strata by fossil depth, predicting occurrence of natural events by rock composition in a particular strata
    MA2015 (6)
    13. Write, read, and evaluate expressions in which letters stand for numbers. [6-EE2]
    a. Write expressions that record operations with numbers and with letters standing for numbers. [6-EE2a]
    Example: Express the calculation, "Subtract y from 5," as 5 - y.
    b. Identify parts of an expression using mathematical terms (sum, term, product, factor, quotient, coefficient); view one or more parts of an expression as a single entity. [6-EE2b]
    Example: Describe the expression 2(8 + 7) as a product of two factors; view (8 + 7) as both a single entity and a sum of two terms.
    c. Evaluate expressions at specific values of their variables. Include expressions that arise from formulas used in real-world problems. Perform arithmetic operations, including those involving whole-number exponents, in the conventional order when there are no parentheses to specify a particular order (Order of Operations). [6-EE2c]
    Example: Use the formulas V = s3 and A = 6s2 to find the volume and surface area of a cube with sides of length s = 1/2.
    MA2015 (6)
    17. Use variables to represent numbers, and write expressions when solving a real-world or mathematical problem; understand that a variable can represent an unknown number or, depending on the purpose at hand, any number in a specified set. [6-EE6]
    SC2015 (4)
    17. Formulate and evaluate solutions to limit the effects of natural Earth processes on humans (e.g., designing earthquake, tornado, or hurricane-resistant buildings; improving monitoring of volcanic activity).*

    Local/National Standards:


    Primary Learning Objective(s):

    The students will set up an algebraic expression using a real world, architectural situation and test the strength of their calculations.

    Additional Learning Objective(s):

    This lesson will be taught collaboratively between the math and science teachers. The math portion of the lesson will be taught during math class and the science portion of the lesson will be taught on the following day during science.

     Preparation Information 

    Total Duration:

    Greater than 120 Minutes

    Materials and Resources:

    • Chart Paper
    • Toothpicks
    • Marshmallows
    • Jello in pan
    • Straws

    Technology Resources Needed:

    Student computers: Students will create a "text-free" digital presentation explaining the importance of building a structure based on math skills. This requires students to explain their presentation rather than read it to their class.


    Math: Print the attached scenarios about treehouses. If groups need to be pre-determined, go ahead and have groups set up.

    Science: Prepare "jelloquake" by bringing premade jello in an unbreakable pan. Divide out materials for building structures to save class time.

    Students: Students will need background knowledge in using variables as unknown numbers. They will need to be able to decipher a word problem and set up an algebraic equation.



    Before: Review the definition of a variable. Discuss that variables are used to take the place of an unknown number in a math problem. Discuss that once the equation is set up correctly, you can find the solution of the unknown number by isolating the variable. Work through an example word problem modeling how to determine what the variable will represent and how to set up the algebraic equation. Divide students into 5 groups.

    During: Each group will be given a word problem about a treehouse (5 different treehouse scenarios are attached). Students will collaborate to set up an algebraic equation to figure out the unknown (the distance between the steps). Once the students have set up their algebraic equation, the teacher will check for correction.

    After: Once students' equation has been approved, give each group a piece of chart paper. Students must draw their treehouse labeling each part of the algebraic equation. Ex: The treehouse is 6 yards high. Students must show that there are 6 yards from the ground to the top of the ladder. There are 24 steps to the treehouse. Students must show 24 steps. After solving the equation on the chart paper, students must show the distance between each step as the variable and it's solution.


    Before: The teacher will begin the lesson by showing the following clip from TeacherTube about earthquakes. 

    During: Students will be given toothpicks and marshmallows to build a structure. They will be given straws to give the structure a base and ladder using the skills learned the previous day in math. Students will be given time to build their structure. Once their structure is complete, place the student's structure on the jello and shake. This will represent the damage done to a structure during an earthquake. Students will see that the more structurally (and mathematically) sound their structure is, the longer it can withstand an earthquake.

    After: Students will create a "text-free" digital presentation explaining the importance of building a structure based on math skills. This requires students to explain their presentation rather than read it to their class (See attached rubric).

    **Some files will display in a new window. Others will prompt you to download.

    Assessment Strategies

    Math: The teacher will assess the students based on correction of the algebraic expression they set up. They will also be assessed on the example tree house they drew on chart paper. The teacher will check for documentation of height of the ladder, number of steps in the ladder, as well as the accuracy of the distance between each step.

    Science: Students will be assessed on the digital presentation created using the attached rubric.





    Each area below is a direct link to general teaching strategies/classroom accommodations for students with identified learning and/or behavior problems such as: reading or math performance below grade level; test or classroom assignments/quizzes at a failing level; failure to complete assignments independently; difficulty with short-term memory, abstract concepts, staying on task, or following directions; poor peer interaction or temper tantrums, and other learning or behavior problems.

    Presentation of Material Environment
    Time Demands Materials
    Attention Using Groups and Peers
    Assisting the Reluctant Starter Dealing with Inappropriate Behavior
    Be sure to check the student's IEP for specific accommodations.