Three Part Lesson: Comparing Heights

This is a summary of the three part math lesson a group of visiting teachers were able to observe in Iain's Grade 3/4 classroom.

Prior Learning:

Prior to this lesson, students in both grades had experiences:

- using a ruler (broken ones that had no zeros so they could focus on the spaces between the numbers)

- measuring objects around the classroom and school

- using decimetres

- conversions between different units

Learning Goal:

Iain felt that students were not getting the 'contexts' in their core text book so he wanted to use a real-life problem that would tell him if he needed to move on in the unit or continue working on this concept.

Groupings:

Students worked in mixed pairs.  Some worked with another person in the same grade while others worked with someone from a different grade level.  Some students chose to work alone.  This was a choice that Iain allowed his students to have.

Part 1: Getting Started

The class had just received a new Promethean board so Iain shared a problem he noticed that students had been having with using it (they can't reach the top).  So he asked the class for some thoughts on how to solve this problem.

Part 2: Working on It

Iain introduced the problem to the whole class.  He shared with the class that he decided to get a stool for students to use when writing on the Promethean board.  But he wanted to know DID HE CHOOSE THE RIGHT STOOL?

To differentiate between the two grades, he got two stools: one for a typical Grade 3 student (Janojan) and one for a typical Grade 4 student (Maaz).

To help students visualize the problem, he got Janojan and Maaz to come up and get measured so students could see exactly how high each student could reach to write on the board.

Of course, everyone in the class wanted to me measured and see how high on the IWB they could reach!

Once students got working, there were several types of strategies used and thinking demonstrated:

STUDENT COULD NOT PROVE HOW HE KNEW JANOJAN COULD REACH THE TOP OF THE BOARD

ADDITION

ADDITION WITH THE USE OF TWO DIFFERENT UNITS

CONVERSION OF UNITS

CONVERSION OF UNITS PLUS REASONING

Part 3: Reflecting and Connecting

While solved this problem, it was obvious to Iain that all of them understood the concept so he did not use a traditional math congress structure to consolidate their understanding.  Instead he asked students: "How do we know he can reach?".  The discussion that followed focused students on the importance of providing proof or evidence to support their answer.

Explicit Teaching:

Iain focused on teaching students how to record and add measurements that have two different units.  For example, 190cm is the same as 1 m 90 cm (Grade 3s) and 175 cm + 3 dm = 205 cm (Grade 4s).