Key Mathematical Ideas

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 all whole numbers, the value of the place farthest to the right is one; the value of all other places is ten times the value of the place to its right.

A study of the result of multiplying any number by 10 reveals aspects of the base-ten structure of the number system.

Examining the different ways in which number lines can be used to represent numbers highlights the relative magnitude of powers of ten.

As students work to learn the number system, their errors highlight the mathematics that underlie the system; for example, we say one hundred ninety-five, but we write 195, not 100905.

Elaborations

The videos below elaborate on the key ideas from this session. This is a great opportunity to consolidate your learning before moving onto the next session. 

Preparation for Session 3

Read Chapter 3: Making Sense of Addition and Subtraction Algorithms from your casebook. Consider the questions posed in the introduction of the chapter.

Session Checkpoint

Click the button below to access your checkpoint form: