## Squares are Special Rectangles

• Lesson
Pre-K-2
3

Students compare and sort rectangles and special rectangles called squares learning to distinguish between the two using their attributes. They will use manipulatives to form squares and rectangles. They will also identify and take pictures of squares and rectangles around school and make a class book.

Before beginning this lesson cut a red square and a blue rectangle from a half piece of construction paper for each student. Also cut a large red square and blue rectangle from a whole piece of construction paper for your demonstration. Place whole pretzel sticks and halved pretzel sticks on plates. Cut in half blue and red construction paper, one of each color per student.

Day 1
Show students a rectangle. Ask: “What can you tell me about this?” [It has 4 straight lines, four corners –if standards require students to be familiar with the word “vertex,” then be sure to include it with any mention of corner in the instructional plan.] Give each student a blue rectangle, and teddy bear counter. Using the teddy bear counter, have students place it on one of the rectangles’ straight lines. Check and make sure everyone did this correctly. As a class and using the teddy bear counter, count the sides of the rectangle. How many sides does the rectangle have? [Four.] Point out that where two sides meet is called a corner. Demonstrate using your large blue rectangle. Have students place their teddy bear counter on one of the corners or vertices. Check to make sure everyone did this correctly. As a class, using a teddy bear counter, count the corners or vertices. How many corners or vertices did your rectangle have? [Four.] Tell students you are going to give them another rectangle. Give students the red square. Ask: “Are these the same or different?” [Different.] “What ways are they different?” [Color and size. Accept any appropriate answers.] Help students realize that the red rectangle has 4 sides just like the blue rectangle, but all of its sides are the same. Have students use their teddy bear counter and count the four sides of the special rectangle. Ask, “What makes the red rectangle special?” [The sides are the same.] Tell students the red rectangle with 4 sides that are the same is called a square.

To review new vocabulary, have students listen carefully and follow directions. Put your teddy bear on the sides of your square. Touch your rectangle’s vertices. Have your teddy bear touch the short sides of your rectangle. Touch the corners of the square. Let your teddy bear touch the long sides of your rectangle.

Have plates of whole pretzel sticks and halved pretzel sticks accessible to each child. Also have red and blue construction paper cut in half and glue available.

Tell students to use the pretzel sticks and make a square on their red piece of construction paper. Once everyone has attempted the task, check everyone’s work by asking:

“What is special about the square?” [All sides are the same length.] Are all of the sides of your square the same? How do you know? Help them to realize that they can compare and measure the pretzel sticks to make sure they are the same size. Have students check their pretzels to make sure they are the same size and allow them to glue them into place to form a square.

Have students use the pretzel sticks to form a rectangle on their blue piece of construction paper. Once everyone has attempted the rectangle, check their work by asking: What is the difference between the square and the rectangle? Both of the shapes students built are rectangles, but the first one was special because all the sides were the same so that one gets the special name of square. Have everyone check their pretzels and allow them to glue them into place forming a rectangle. Walk around room, giving help when needed. What did the square and rectangle have that were the same? [Four straight sides and four corners.] What makes the square special? [The sides are the same length.] Using a premade example with a square glued to a piece of blue construction paper, ask students if it’s an example of a square or a rectangle or both? [Two rectangles and one square.]

Display work in room and use as a review.

Day 2
Begin the lesson by reviewing the activity from the day before where the students constructed squares and rectangles from pretzel sticks.

Ask: “How many sides and corners does a rectangle have?” [They have 4 straight sides, and 4 corners.] What makes the square a special rectangle? [The square has 4 sides that are the same] Pass out the Squares and Rectangles activity sheet. Instruct students to use a blue crayon to color all of the rectangles. Remind them that a rectangle has 4 sides and 4 corners. Walk around the room making sure each student can identify all rectangles, including the special rectangles called squares. Next have students use a red crayon to circle the special rectangles that are squares. Remind them that a square has 4 sides that are the same length. Walk around the room making sure each student can distinguish between squares and rectangles.

 Squares and Rectangles Activity Sheet

As a class take a walk around the school looking for rectangles and special rectangles called squares. When one is identified, explore the shape and decide if it meets the criteria of a rectangle or square. Any shape identified as a square can also be correctly identified as a rectangle. If students find a square, ask what other name we can give that shape? [Rectangle.] Why is it both? [Because a square is a special rectangle.] Examples of things you may see around the school are doors, signs, and tiles.

Next take pictures with students pointing to the shapes. Print pictures and have them ready for the next day’s lesson.

Day 3
As a class, use the pictures from the walk around school and have students sort them into special rectangles called squares and other rectangles. As they sort pictures, ask students why they think it is a rectangle or square. Encourage them to use vocabulary such as straight lines, corners, etc….

Construct a class book of special rectangles called squares and other rectangles. Allow students to glue and label the pictures. Share book during circle time allowing students to describe the pictures and justifying the decisions they made when determining if it was a rectangle or a special rectangle called a square.

The students will enjoy looking at their pictures and interacting with the book. This book will get looked at over and over therefore making it a great review of rectangles and squares, and how these shapes are represented in the world around them.

Assessments

1. Students completed pretzel project will give the teacher an understanding of which students understand the difference between a rectangle and a special rectangle called a square.
2. The student’s group participation will aid in helping determine the student’s level of understanding.
3. Give students 4 square tiles and ask them to construct a square. Then ask them to use the same 4 square tiles to construct a rectangle. Have the students explain why it is a square or rectangle making sure they are expressing themselves using the vocabulary they learned from the lesson.

Extensions

1. Make a list of squares and rectangles in the classroom, or have students bring in an example of a square or rectangle from home. Graph this information using a class graph to see if students found or brought in more rectangles or more special rectangles called squares. .
2. Give students a pile of paper squares. Ask them to put squares together to find as many different squares and rectangles as they can. Each shape cannot use more that 6 paper squares. After they finish, discuss their findings.

Questions for Students

1. How many straight sides does a rectangle and square have?

[4.]

2. When two sides meet they form a?

[Corner.]

3. How many corners or vertices does the rectangle and square have?

[4.]

4. What makes the square a special rectangle?

[All four sides are the same length.]

5. What kind of squares did we find around the school?

6. What kind of rectangles did we find around the school?

Teacher Reflection

• Were the students able to construct rectangles and squares using the pretzels?
• Were the students able to distinguish between the two shapes and color them the correct color?
• Did all students participate in finding squares and rectangles around the school?
• Were they able to use the information they learned about rectangles to differentiate between the two shapes as you explored the school grounds?
• Were the students able to use the correct vocabulary when describing the two shapes?
• Did all students participate in sorting the pictures for the class book?
• Were all students excited to revisit the class book of rectangles and squares?

### Learning Objectives

Students will:

• Name, describe and sort squares and rectangles. Use manipulatives to build squares and rectangles
• Recognize these shapes in their environment

### Common Core State Standards – Mathematics

-Kindergarten, Measurement & Data

• CCSS.Math.Content.K.MD.B.3
Classify objects into given categories; count the numbers of objects in each category and sort the categories by count.

-Kindergarten, Geometry

• CCSS.Math.Content.K.G.A.1
Describe objects in the environment using names of shapes, and describe the relative positions of these objects using terms such as above, below, beside, in front of, behind, and next to.

-Kindergarten, Geometry

• CCSS.Math.Content.K.G.A.2
Correctly name shapes regardless of their orientations or overall size.

-Kindergarten, Geometry

• CCSS.Math.Content.K.G.B.4
Analyze and compare two- and three-dimensional shapes, in different sizes and orientations, using informal language to describe their similarities, differences, parts (e.g., number of sides and vertices/''corners'') and other attributes (e.g., having sides of equal length).

• CCSS.Math.Content.2.G.A.1
Recognize and draw shapes having specified attributes, such as a given number of angles or a given number of equal faces. Identify triangles, quadrilaterals, pentagons, hexagons, and cubes.

### Common Core State Standards – Practice

• CCSS.Math.Practice.MP1
Make sense of problems and persevere in solving them.
• CCSS.Math.Practice.MP4
Model with mathematics.
• CCSS.Math.Practice.MP5
Use appropriate tools strategically.
• CCSS.Math.Practice.MP7
Look for and make use of structure.