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Learning Objectives
Students will be able to divide circles and rectangles into equal parts and identify halves.
Introduction
(5 minutes) Ask students to give you a thumbsup if they have ever eaten birthday cake.
 Tell students to imagine a small birthday cake, and draw a circle on the board.
 Say something like, "My friend and I are going to split this birthday cake." Draw a line diagonally across the cake, but do not divide the circle in half.
 Say, "My friend thinks this is a fair way to share the cake." Ask students whether they think the cake is divided equally. Have students explain their thinking, and talk about how they notice that one piece of the circle is bigger than the other.

Beginning:
 Show students a picture of an actual birthday cake
 Label the unequal parts "smaller" and "bigger."
 Partner with a student who speaks same home language (L1), and have the pair explain why the cake is not divided fairly in L1.
 Intermediate:
 Provide the sentence stem, "The cake is not divided equally because __ __ __ __" and have students share thinking with a partner.
Explicit Instruction/Teacher modeling
(5 minutes) Erase the line you drew and have a student volunteer come to the board and divide the cake fairly.
 Explain that the student divided the cake in half. Write "1 half" on each equal part of the circle. Use the word "half" rather than the fraction symbol.
 Think aloud by saying, "Sometimes I have been to birthday parties where the cake is a rectangle instead of a circle." Draw a rectangle on the board.
 Guide students in thinking about ways to divide the rectangle into equal shares. Have a student volunteer come to the board to divide the rectangle in half.
 Acknowledge the student for dividing the rectangle into two equal parts, and label each part "1 half." Ask students to show you by positioning their arms other ways to divide the rectangle in half.
 Draw two more rectangles on the board, and agree that the rectangle could be cut up and down (vertically), back and forth (horizontally), or corner to corner (diagonally). Label the halves.
 Ask students whether they would each get more or less cake after dividing the cake with their friend. Point out that when the cake is divided in half, each person gets a smaller amount.
 Beginning:
 Tell students to repeat vocabulary word "half" as you point to one half of the circle.
 Remind students that an "equal sign" is used to show that two sides of an equation are the same. Here, "equal" means that the two parts are the same size.
 Intermediate:
 Tell students that the "l" is silent in the word "half," like the silent "e" in "bike." The word is pronounced with just three sounds: haf.
Guided Practice
(5 minutes) Create a Tchart titled "Equal and Unequal Parts."
 Show students the images from the Equal/Unequal Parts worksheet examples.
 Have students give you a thumbsup if the parts are equal and a thumbsdown if the parts are not equal.
 Have students come tape the shape in the appropriate column of the Tchart as you show students the examples.

Beginning:
 Sort the cards with a small group of students. Students should tell you "The parts are equal" or "The parts are unequal" as they sort the shapes.
 Intermediate:
 Instruct students to draw and sort examples of shapes divided into equal and unequal parts with a partner.
Independent working time
(15 minutes) Distribute the Divide the Shape in Half worksheet to the class. After you check that students have correctly divided the shapes, have them color one half of each shape.
 Beginning:
 Instruct students to work with a partner as they complete the worksheet. Write the question "Is there a different way to divide the shape in half?" on the board. Challenge students to divide the shapes in different ways.
 Students can practice folding paper to build understanding of halves.
 Intermediate:
 Students can draw a large shape on the back of the paper, divide it in half, and label each part "one half."
 Display and label examples of horizontal, vertical, and diagonal lines on the board. Prompt students to describe the line they used to divide the shape with the sentence frame, "I divided the shape in half with a __ __ __ __ line."
Differentiation
Support:
 Provide students with more examples and nonexamples of shapes divided into equal parts.
 Pull students to work in a teacherled small group.
Enrichment:
 Have students label each equal part "one half."
 Have students create their own Tchart with examples and nonexamples of shapes divided into equal parts on the back of the worksheet.
 Have students complete the Four Equal Quarters worksheet
Assessment
(5 minutes) Ask students to explain how they know that the shapes are divided into equal parts.

Beginning:
 Take note of any shapes that students struggle to divide in half, and review these whole class.
 Intermediate:
 Tell students to explain the steps they followed to divide the shapes in half with a partner.
Review and closing
(5 minutes) Collect student work and call students back to the rug.
 Show students another example of dividing a whole into two halves by holding up a piece of string.
 Cut the string into unequal parts. Hold both pieces of string up next to one another and ask students to give you a thumbsup if the parts are equal.
 Cut another piece of string into equal parts. Hold up the pieces so that students see both pieces are the same length.
 Remind students, "I just cut the string in half."

Beginning:
 Provide string, strips of paper, and straws for students to practice dividing items in half as a small group or center activity.
 Intermediate:
 Ask students to name things can be divided in half, such as sandwiches or pizza.