Zooming In On Figures

Unit Overview

Type of Unit: Concept; Project

Length of Unit: 18 days and 5 days for project

Prior Knowledge

Students should be able to:

Find the area of triangles and special quadrilaterals.
Use nets composed of triangles and rectangles in order to find the surface area of solids.
Find the volume of right rectangular prisms.
Solve proportions.

Lesson Flow

After an initial exploratory lesson that gets students thinking in general about geometry and its application in real-world contexts, the unit is divided into two concept development sections: the first focuses on two-dimensional (2-D) figures and measures, and the second looks at three-dimensional (3-D) figures and measures.
The first set of conceptual lessons looks at 2-D figures and area and length calculations. Students explore finding the area of polygons by deconstructing them into known figures. This exploration will lead to looking at regular polygons and deriving a general formula. The general formula for polygons leads to the formula for the area of a circle. Students will also investigate the ratio of circumference to diameter ( pi ). All of this will be applied toward looking at scale and the way that length and area are affected. All the lessons noted above will feature examples of real-world contexts.
The second set of conceptual development lessons focuses on 3-D figures and surface area and volume calculations. Students will revisit nets to arrive at a general formula for finding the surface area of any right prism. Students will extend their knowledge of area of polygons to surface area calculations as well as a general formula for the volume of any right prism. Students will explore the 3-D surface that results from a plane slicing through a rectangular prism or pyramid. Students will also explore 3-D figures composed of cubes, finding the surface area and volume by looking at 3-D views.
The unit ends with a unit examination and project presentations.

Lesson OverviewStudents will compare the formula for the area of a regular polygon to discover the formula for the area of a circle.Key ConceptsThe area of a regular polygon can be found by multiplying the apothem by half of the perimeter. If a circle is thought of as a regular polygon with many sides, the formula can be applied.For a circle, the apothem is the radius, and p is C.A=a(p2)→A=rC2→A=rπd2→A=rπ2r2→A=rπr=πr2 GoalsDerive the formula for the area of a circle.Apply the formula to find the area of circles.SWD: Consider the prerequisite skills for this lesson: understanding and applying the formula for the area of a regular polygon. Students with disabilities may need direct instruction and guided practice with this skill.Students should understand these domain-specific terms:apothemparallelogramderivationheightapproximate (estimate)scatter plotpiperimetercircumferenceIt may be helpful to preteach these terms to students with disabilities. 

Students will measure the circumference and diameter of round things in the classroom and discover the ratio pi. They will see that the ratio of a circle's circumference to its diameter can be used to solve for the circumference when the diameter is known.Key ConceptsStudents have seen circles before, but have not analyzed the relationships between parts of a circle. The ratio of the circumference to the diameter is pi, about 3.14 or about 227. Students see that all of the objects they measure have this ratio (or close, depending on accuracy) and that the ratio is true for all circles. Students also see that the ratio can be used to solve for the circumference of a circle if the diameter (or radius) is known.GoalsMeasure round things looking for similarities.Find the ratio of the circumference to the diameter of those round things.Find a formula to find the circumference of a circle.SWD: Make sure students understand these domain-specific terms:It may be helpful to preteach these terms to students with special needs. If possible, reinforce the definitions of these terms with visual supports (diagrams).ELL: As new vocabulary is introduced, be sure to repeat it several times and to allow students to repeat after you as needed. Write the new words as they are introduced and allow enough time for ELLs to check their dictionaries or briefly consult with another student who shares the same primary language if they wish.ratiocircumferencecirclediameterscatter plot

Lesson OverviewStudent groups make their presentations, provide feedback on other students’ presentations, and get evaluated on their listening skills.Key ConceptsIn this culminating event, students present their project plan and solution to the class. The presentation allows students to explain their problem-solving plan, communicate their reasoning, and construct a viable argument about a mathematical problem.Students also listen to other project presentations and provide feedback to the presenters. Listeners have the opportunity to critique the mathematical reasoning of others.GoalsPresent project to the class.Give feedback on other project presentations.Exhibit good listening skills.Reflect on the problem-solving process.

Students will join the buildings together to form a city with streets and sidewalks running between the buildings. Student groups will make their presentations, provide feedback to other students’ presentations, and get evaluated on their listening skills.Key ConceptsIn this culminating event, students  present their project plan and solution to the class. The presentation allows students to explain their problem-solving plan, communicate their reasoning, and construct a viable argument about a mathematical problem.Students also listen to other project presentations and provide feedback to the presenters. Listeners have the opportunity to critique the mathematical reasoning of others.GoalsPresent projects and demonstrate understanding of the unit concepts.Clarify any misconceptions or difficult areas from the Final Assessment.Give feedback on other project presentations.Exhibit good listening skills.Review the concepts from the unit.

This lesson unit is intended to help you assess how well students are able to: Interpret a situation and represent the variables mathematically; select appropriate mathematical methods to use; explore the effects on the area of a rectangle of systematically varying the dimensions whilst keeping the perimeter constant; interpret and evaluate the data generated and identify the optimum case; and communicate their reasoning clearly.

Driving Question: How can we as 7th grade math students use surface area to make a mug that retains heat for the longest amount of time possible?

This goal of this task is to give students familiarity using the formula for the area of a circle while also addressing measurement error.

 This problem-based learning module is designed to engage students in solving a real problem within the community.  The question being “How can I help my community get digitally connected?”  Students will choose to investigate one of three solutions of making wifi available in our school district to the most populated areas. They will either choose to put Wifi on bus, placing hotspots in the community or using kajeet.   The students will be using Google Earth Pro to place circles on a map and calculating the area of these circles.  Students will make a model of these circles onto a hard copy using scale factor. At the conclusion, the students will present findings to administration, the board of education, state and local leaders as well as their peers.  These findings can be presented through the choice of a display board, flyer, video production or prezi.This blended module includes teacher-led discussion, group-led investigation and discussions along with technology integration.

The intent of clarifying statements is to provide additional guidance for educators to communicate the intent of the standard to support the future development of curricular resources and assessments aligned to the 2021 math standards.  Clarifying statements can be in the form of succinct sentences or paragraphs that attend to one of four types of clarifications: (1) Student Experiences; (2) Examples; (3) Boundaries; and (4) Connection to Math Practices.

Students are introduced to renewable energy, including its relevance and importance to our current and future world. They learn the mechanics of how wind turbines convert wind energy into electrical energy and the concepts of lift and drag. Then they apply real-world technical tools and techniques to design their own aerodynamic wind turbines that efficiently harvest the most wind energy. Specifically, teams each design a wind turbine propeller attachment. They sketch rotor blade ideas, create CAD drawings (using Google SketchUp) of the best designs and make them come to life by fabricating them on a 3D printer. They attach, test and analyze different versions and/or configurations using a LEGO wind turbine, fan and an energy meter. At activity end, students discuss their results and the most successful designs, the aerodynamics characteristics affecting a wind turbine's ability to efficiently harvest wind energy, and ideas for improvement. The activity is suitable for a class/team competition. Example 3D rotor blade designs are provided.

Students learn about the variety of materials used by engineers in the design and construction of modern bridges. They also find out about the material properties important to bridge construction and consider the advantages and disadvantages of steel and concrete as common bridge-building materials to handle compressive and tensile forces.

In this activity, students act as environmental engineers involved with the clean up of a toxic spill. Using bioremediation as the process, students select which bacteria they will use to eat up the pollutant spilled. Students learn how engineers use bioremediation to make organism degrade harmful chemicals. Engineers must make sure bacteria have everything they need to live and degrade contaminants for bioremediation to happen. Students learn about the needs of living things by setting up an experiment with yeast. The scientific method is reinforced as students must design the experiment themselves making sure they include a control and complete parts of a formal lab report.

In this activity, students learn how engineers design faucets. Students will learn about water pressure by building a simple system to model faucets and test the relationship between pressure, area and force. This is a great outdoor activity on a warm day.

This lesson unit is intended to help you assess how well students are able to: recognize and use common 2D representations of 3D objects and identify and use the appropriate formula for finding the circumference of a circle.