How Many Squares?

• Demonstrate how to partition the birthday cake into pieces by creating columns and rows using the color tiles.
• Point to the columns and explain that they are called columns, a column is a number of items in a straight vertical line. Point to the rows and explain that a row is a number of things in a straight horizontal line. Explain that we use both rows and columns as a way to group something together to organize it.
• Use the think aloud strategy to show how you can determine how many rows, columns, and total number of cake pieces you have.
• Explain to the class that you have just partitioned your cake. Partition means to divide something into equal pieces.

• Display another blank rectangle on the projector.
• Ask your students how they could partition the rectangle using four rows and four columns.
• Have students turn and talk to a partner to share their ideas.
• Invite one or two students to come to the front of the class and demonstrate how they would partition the rectangle using the color tiles.
• Support the students by counting each row and column and helping them figure out the total number of squares in the rectangle.
• Tell the students that they will now get to practice partitioning a shape on their own.

• Pass out the Divide It!: Rows and Columns worksheet and explain that students can use any of the math manipulatives you have provided (snap cubes, square color tiles, pre-cut paper squares, or similar material used for counting squares) to answer the questions.

Support

• Gather a small group of students together to complete the worksheet as a group.
• Use graph paper to help students visualize the rows and columns, outline a rectangle and have students color in the squares.

Enrichment

• Have students complete the How Big is Your Room worksheet as an extension to this lesson.

• While students are working independently, ask them guiding questions about their work.
  • How many columns are there? How many rows? How do you know? How many total squares are there? How can you double check your work?
• Collect student work samples to check for accuracy at the end of the lesson.

• Display one or two student worksheets on the projector.
• Identify the number of columns, rows, and total number of squares on the worksheet.
• Answer any of your students' questions as needed.