Co-Teaching Lesson: Measuring Area (Joan/Honey)

Here is a summary of the Grade 2 Measurement lesson we observed during our co-teaching session at Bendale JPS.  Thank you, Joan and Honey, for being our co-teachers!
Three-Part Lesson Plan and Assessment for Learning Tool

Prior Learning:
Students in both classes had prior experiences using a variety of tools to solve measurement problems.  This lesson was in the middle of their study of area.

Prior to today's lesson, students had a chance to figure out which one had the greatest area: their hand print or footprint.

Part 1: Getting Started
Honey asked students to share they did and figured out the day before with a partner.

Students then had a chance to share the strategy they used to figure the area of their own hand and foot print.  Honey recorded their ideas on chart paper.

Part 2: Working on It
Joan introduced the problem to the whole class.

For this problem, students were given two mystery hand prints and footprints.

As a class, students and Joan discussed what the word 'justify' meant.  Together, they decided that it meant ' prove what you decided is right".

Students were reminded of all the different tools that were available to them when solving this problem.

There were several strategies and misconceptions we observed as students worked on solving the problem.  Here are a few:

Different units to used to measure the area so it makes it difficult to compare measurements.

Manipulative chosen spills over so the area appears larger that what it actually is.

The same unit was chosen to compare areas but the coins leave spaces.

Created a grid to determine area but the grids are not all the same size, so you cannot compare accurately.

Part 3: Reflecting and Connecting (Consolidation)
Joan and Honey used the math congress strategy to consolidate students understanding of the key ideas in this lesson.  Based on what was observed in student work, Joan and Honey strategically chose several pairs to share. The intent was to clarify and make a key point:

Key point: the pennies fit in the hand print and footprint nicely but there are spaces in between them.  This will not give us an accurate measure of the area.

The cubes do not leave any spaces in between them but they spill out of the shape.  The measurement of area will not be accurate.

The centicubes are a good tool to measure the area of the hand and footprints because it does not spill over nor leave any spaces.

Part 3: Explicit Teaching
Many students understood the key ideas in the lesson through the math congress.  However, students noticed that the smaller the unit, the more accurate the measurement.  Honey and Joan plan on pursuing this key concept the following day.