ALEX Learning Activity

  

Finding the Unknown Side of Safety Signs

A Learning Activity is a strategy a teacher chooses to actively engage students in learning a concept or skill using a digital tool/resource.

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  This learning activity provided by:  
Author: Stephanie Carver
System:Cullman City
School:Cullman City Board Of Education
  General Activity Information  
Activity ID: 2806
Title:
Finding the Unknown Side of Safety Signs
Digital Tool/Resource:
Unknown Side of Safety Signs Activity Sheet
Web Address – URL:
Overview:

This learning activity allows students to explain their thinking to find the unknown side of a polygon when the perimeter is given. Students will solve three different problems where the perimeter is given and knowledge of polygon attributes are needed to find the missing sides. This activity can be used as an assessment or an extension activity after students have mastered how to find the perimeter of a polygon. 
  Associated Standards and Objectives  
Content Standard(s):
Mathematics
MA2019 (2019)
Grade: 3
25. Solve real-world problems involving perimeters of polygons, including finding the perimeter given the side lengths and finding an unknown side length of rectangles.
Unpacked Content
Evidence Of Student Attainment:
Students:
  • Measure to find the perimeter of shapes.
  • Given a figure, determine the perimeter of the figure.
  • Given a figure with a missing side length and a given perimeter, determine the missing side length.
  • Solve real-world problems involving perimeters of polygons.
  • Use a multiplication expression to find perimeter of a polygon when all side measures of the polygon are equal.
Teacher Vocabulary:
  • Attribute
  • Dimension
  • Perimeter
  • Polygon
  • Two-dimensional
Knowledge:
Students know:
  • Measurable attributes of objects, specifically perimeter.
  • Strategies for modeling measurement problems involving perimeter.
  • Strategies for representing and computing perimeter.
Skills:
The Students are able to:
  • Solve real-world and mathematical problems involving perimeters of polygons.
  • Find the perimeter of a figure given the side lengths.
  • Find an unknown side length of a polygon given the perimeter and one missing side length.
Understanding:
Students understand that:
  • Perimeter is measured in length units and is the distance around a two-dimensional figure.
  • If all the sides of a polygon are equal, then the perimeter can be determined by multiplying one side length by the total number of sides.
Diverse Learning Needs:
Essential Skills:
Learning Objectives:
M.3.25.1: Define perimeter.
M.3.25.2: Recall the formula for perimeter (P= L+L+W+W or P=2L + 2W).
M.3.25.3: Recall basic addition and multiplication facts.
M. 3.23.4: Build and draw shapes to possess defining attributes.
M.3.25.4: Express the length of an object as a whole number of length units by laying multiple copies of a shorter object (the length unit) end to end; understand that the length measurement of an object is the number of same-size length units that span it with no gaps or overlaps.
M.3.25.5: Describe measurable attributes of objects such as length or weight.

Prior Knowledge Skills:
  • Recall doubles addition facts.
  • Model written method for composing equations.
Alabama Alternate Achievement Standards
AAS Standard:
M.AAS.3.20 Find the area of a given shape using arrays (unit cubes and tiles) in relationship to multiplication. Limit units to 25.

Learning Objectives:

Students will find the unknown side length of polygons when the perimeter is given. 
  Strategies, Preparations and Variations  
Phase:
After/Explain/Elaborate
Activity:

  1. The teacher will distribute the Unknown Side of Safety Signs Activity Sheet.

  2. The teacher will explain to the students that they will use the Unknown Side of Safety Signs Activity Sheet to solve for the unknown side of safety signs.

  3. The teacher will remind the students they must find the unknown side when given the perimeter. The students will need to use prior knowledge of polygon attributes. (This activity can be completed independently or with partners.)

  4. At the end of class, the teacher can start a class discussion while taking up the activity sheet for assessment purposes.
Assessment Strategies:

The teacher will have the students complete the Unknown Side of Safety Signs Activity Sheet for assessment measures.
Advanced Preparation:

  • The teacher will need to make copies of the activity sheet prior to the learning activity. 

  • Students will need background knowledge of polygon attributes and how to find the perimeter of a polygon. 
Variation Tips (optional):
 
Notes or Recommendations (optional):

This activity can stand alone or be used as an After/Explain/Elaborate activity for the following learning activities:

 

Perimeter Introduction Activity (Before activity)

Perimeters of Pools (During activity)
  Keywords and Search Tags  
Keywords and Search Tags: length, perimeter, polygon, unknown side, width