Three Part Lesson: Rounding and Estimating

This is a summary of the three part math lesson we were fortunate to observe in Iain's Grade 3/4 classroom.

Prior Learning:

Prior to this lesson, students explored numbers.  This is an anchor chart Iain created with both grade levels.

Learning Goal:

Iain wanted students to understand when to use precise numbers and when to use rounded or estimated numbers.  In addition to this, he wanted both grade groups to understand how to round by 10, 100, and 100.

Groupings:

Students worked in mixed pairs.  Some worked with someone else 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

Using a think-pair-share, Iain reviewed previous discussions about when to use precise (or exact) numbers or when to estimate.  He also reviewed the anchor chart with the whole class (Grades 3+4)

Part 2: Working on It

Iain introduced the problem to the whole class.  He was very intentional about choosing a real life context for this lesson.

As students worked on the problem, they used several strategies to solve this problem:

Problem Solving Strategy: Draw a picture or Diagram

Problem Solving Strategy: Draw a table

Problem Solving Strategy: Logical Reasoning

Problem Solving Strategy: Repeated Addition

Part 3: Reflecting and Connecting

Instead of using a traditional math congress structure, Iain got all pairs to partner up with each other and share their thinking with each other.  

 Explicit Teaching;

After hearing from a few pairs about their strategy, Iain explicitly taught both grade groups how to round by 10, 100, and 1000.

Independent Practice:

Iain differentiated the independent practice of the concepts by asking students to complete specific questions from their core text book.