The purpose of this activity is for students to compare two objects to determine which object is longer or shorter. In the previous lesson, students used "longer than" and "shorter than" to describe the lengths of rectangles. Because the rectangles were lined up, students only needed to find the longer rectangle. In this activity, students compare the length of straws that will be used to build shapes in the next activity. As students work, monitor for students who line up the straws at the endpoints when they compare length. The Activity Synthesis focuses on why lining up at the endpoints is helpful to accurately compare the lengths of objects (MP6).

• Display 2 straws arranged as shown.

  

• “Clare was comparing the lengths of the straws. She says that the blue straw is longer than the red straw because it sticks out more. What do you think?” (We can’t tell. The blue straw is sticking out more, but it doesn't start at the same place.)
• “When we’re comparing the lengths of objects, we should line them up at their ends.”
• Line up the the straws as shown:

  

• “Tell your partner about the lengths of the straws, using the words ‘shorter than.’”
• Invite previously identified students to share how they compared the lengths.
• Draw or display a rectangle:

  

• “In the next activity, we will use straws to build shapes like this rectangle. What kind of straws do you need to build this shape?” (I need 2 long straws and 2 shorter straws.)

• “Use 3 straws to create a shape.”
• 30 seconds: independent work time
• Display 3 student-created triangles.
• “How are the shapes alike? How are they different?”
• 30 seconds: quiet think time
• 30 seconds: partner discussion
• Monitor for students who identify the shapes as triangles. Monitor for students who describe the different lengths of the sides.
• Share responses.
• Repeat the steps, with students using 4 straws to create a shape. Display at least 1 square.

The purpose of this activity is for students to learn Stage 1 of the Build Shapes center. Students choose a shape from the gameboard and use straws and clay to build that shape. Students make sure that their partner agrees that the shapes they built match the shape on the gameboard. Listen to how students create an argument and use or revise language to make their argument clear (MP3, MP6).

After they participate in the center, students choose from any stage of previously introduced centersL

• Counting Collections
• Which One?
• Picture Books
• Bingo
• Shake and Spill

• Display a square built from 4 straws that are the same length.
• Display a rectangle from the gameboard.
• “Han was trying to build this shape. What should Han change so his shape will match the shape on the card?”