Science learning can seem like learning an alien language. Learning science includes learning and using many new languages - scientific practice terms, content-specific vocabulary and the words associated with new systems - like the metric system of measurement! In this lesson, students are introduced to the metric system and practice using the metric system to measure many different quantities.
Because the metric system is the language of measurement for scientific practice world wide (almost!), learning this system is important for understanding and participating in global science practice. The understanding that standard units are used to measure and describe physical quantities such as weight, time, temperature, and volume (CCC - Scale, proportion, and quantity) is a crosscutting concept deeply ingrained in this lesson.
Additionally, math standards apply too; students work to understand relative sizes of measurement units within one system of units (4.MD.A.1) and use ratio reasoning to convert measurement units (6.RP.A.3d). An understanding of the metric system allows students to participate in effective collection of data to serve as the basis for evidence to answer scientific questions or test design solutions under a range of conditions (SP3).
This lesson is the introductory lesson to what amounts to year-long (and life-long) practice of the metric system. Just as in learning a language, best practice is immersion. While the following related lessons help students learn the unique units and measurement practices for different physical quantities, teaching these lessons in context provides more leverage for student learning. Rather than embarking on a stand-alone unit for the metric system, students learn and retain the information when they practice the skills within the context of meaningful investigation.
In order to ENGAGE students in this lesson, using the Metric System Presentation students consider this prompt:
The EXPLORE stage of the lesson is to get students involved in the topic so that they start to build their own understanding. To help students explore the metric system, they participate in a series of activities designed to introduce and build knowledge:
2) After a brief discussion, students watch the Powers of Ten video to determine:
What happens when you multiply or divide by 10?
How does basing a measurement system based the on number 10 make using the system more efficient?
3) At this point, students update their Metric System Student Handout to complete a brief explanation of the main factors important to the metric system:
- is a system of measurement based on the number 10.
- is used by all scientists and most countries as a common language of measurement.
The metric system is also known as SI (International System of Units).
Have students view slide 5 of the Metric System Presentation to illustrate the power of 10 and preview metric unit prefixes. Slide 6 shows a map of how few countries don't use the metric system, which visually illustrates to students about the importance of sharing a common language for measurement.
4) Now that students have a very basic understanding, they will embark on a brief research odyssey to explore a few quantities and how they are measured using the data table on the Metric System Student Handout. To excite students, have them read this brief excerpt from the Metric Conversion Act and remind them that if they don't use the metric system, they are actually breaking the law!
5) The last part of the exploration process is for students to complete the final section of the Metric System Student Handout to become familiar with prefixes and base units and how, in the metric system, units can be made smaller or larger by adding a PREFIX to the basic metric unit.
For a fun application for using the metric system, read this section's reflection: Metric Ball Using the Metric System for Fun.
The EXPLAIN stage provides students with an opportunity to communicate what they have learned so far and figure out what it means. This stage of the lesson presents a great place for a quick formative assessment. A quick review of student work (Measuring in Metric Student Work) using the Metric System Student Handout Notes as a class is a great way to elicit student explanations and check for understanding:
The EXTEND stage allows students to apply new knowledge to a novel situation. The novel situation in this case is further understanding of how to convert between metric units. For many students, retention of basic metric units that are commonly used (meters, centimeters, millimeters, grams, liters, milliliters, etc.) and the skills required to measure quantities is enough. However, for students with advanced understanding, practice with converting units is developmentally appropriate: Metric System Extensions.
The EVALUATION stage is for both students and teachers to determine how much learning and understanding has taken place. As noted in the introduction to this unit, this lesson is a first exposure lesson to the metric system. Appropriate evaluation after implementation of this lesson would include a basic "remembering" assessment such as Measurement Quiz - Multiple Choice or Measurement Quiz.
After students learn the unique units and measurement practices for different physical quantities within the context of meaningful investigation, a more comprehensive evaluation would be appropriate. For review of these concepts, the Matter Measurement Summary is an effective way for students to summarize and explain the concepts associated with measurement (as is evident in Measuring Matter Student Work). This Metric Measurement Review Activity helps students self-assess their understanding prior to a comprehensive evaluation: Metric Measurement Assessment.