In Session 1, you began to explore what it means to measure. In this session, you will investigate the difference between a count and a measure and examine some of the important ideas essential to meaningful measurement. You will learn about the many uses of ratio in measurement and how scale models can help us understand relative sizes. Finally, you will investigate the constant of proportionality in isosceles right triangles and learn about precision and accuracy in measurement.

For the list of materials that are required and/or optional in this session, see Note 1.

Part A:	Measuring Accurately
Part B:	The Role of Ratio
Part C:	Precision and Accuracy
Homework

In this session, you will do the following:

Understand the three components of measuring: conservation, transitivity, and unit iteration

Consider the effects of partitioning a unit into smaller subunits

Understand the use of proportional reasoning and ratio in measurement situations

Use accuracy and precision to determine how much error is involved in any given measurement

Throughout the session you will be prompted to view short video segments. In addition to these excerpts, you may choose to watch the full-length video of this session.

Previously Introduced:

New in This Session:

measurement
precision

accuracy
compensatory principle
conservation
partitioning
ratio
scale
scale factor
transitivity
unit iteration

Learning Math Home | Measurement Home | Glossary | Map | ©

Session 2: Index | Notes | Solutions | Video