Developing Mathematical Ideas
Collaborative Professional Learning for K-Grade 8 Teachers

Number and Operations Part 1:
Building a System of Tens

Calculating with Whole Numbers and Decimals

Session 2: Seminar Preparation

The Facilitator’s Checklist contains links to the readings, video, and downloadable materials you will need to prepare for and lead Session 2.

Your Detailed Agenda

Download the MS Word–formatted version of the Detailed Agenda to adapt and annotate with your personal notes.

In-Class Agenda and Video

Facilitator Checklist


Work through

  • Focus questions
  • Math activity: Multiplying by 10


Video: Interviews with three students 

Download and copy



Poster stating the main idea of the session:

The value of a number is determined by multiplying the value of each digit by the value of the place that it occupies and then summing. For whole numbers, the value of the place farthest to the right is one; the value of every other place is ten times the value of the place to its right.


  • base-ten blocks
  • index cards
  • interlocking cubes