Measurement 4.1

Directly Measuring Area and Volume

WATCH: The Challenge of Measuring Area

Measuring area is arguably the most challenging attribute to measure directly. Watch this video as it describes why this is the case and then introduces a tool to make measuring area more bearable.

Discuss

Reflect on the ideas in the video and talk about your own experiences of teaching area, including any challenges your students have had with this concept.

TASK: Analyzing Student Work

Watch these two videos of Blake, a grade 7 student, as he uses an array to find the area of a rectangle.

Discuss

What does Blake know about area and what does he still need to learn?

What is Blake thinking as he sets out the paper tiles?

What focus questions does Blake's teacher use to encourage him to find a shortcut? And how did they nudge Blake's learning forward?

Discuss

Blake appears to be using the array structure to work out how many squares fit in the rectangle. However he is not able to use the array idea to help him know how many part units he would need across the base.

Why does Blake have difficulty working out the area of the part units? How does the teacher's prompt help him? What else might you do to help Blake advance?

Share

Record highlights from your discussion about Blake and the challenges of directly measuring area in the Collaborative Notebook.

Want to Dig Deeper?

Read more about some of the big ideas involved in measuring area and volume. Use this reading to further clarify some of the challenges around measuring area and volume and some of the instructional moves that can help develop the associated concepts and skills.

As a facilitation strategy, you could assign sections of this article to different group members and have each member share a summary of their reading with the group

CONSOLIDATE and SHARE

Watch: Revisiting Blake

Consider how the deliberate choice of materials can help nudge students away from a "cover and count" approach to directly measuring area to the more practical shortcuts of indirectly measuring area.

Discuss and Share

Talk with your team about the five tips mentioned in the video on how materials can provoke learning about area. What struck you as being significant? Were there any ideas that you wanted to push back against or new questions that arose? What are some of your own ideas for how to help students advance in their understanding of measuring area?

Record your thoughts in the Collaborative Notebook.