Units & Systems

This unit introduces students to some of the scientific terminology used for measurement and clarifies some of the misunderstandings that students have around important measurement vocabulary. Additionally, students create an original measurement system and present their system to the class.

Activities

Scene: The Importance of Units

Emon, Markus, Yesinia, Kaitlyn, and Haitham consider the multiple definitions of "unit." and their misunderstandings of the related terminology. Questions check comprehension and spark discussion as students practice using scientific language.

Duration: Approximately 50 minutes

Lesson: Concepts, Confusion, and Comparisons

Students distinguish terms used for measurement: mass/weight, volume/capacity, and length/distance. Using cut-up word strips, students work in pairs to create sentences that are accurate and that make sense. Students “upgrade” their language to more precise and formal scientific language. Finally, they make two comparisons in two styles: as informal, less precise comparison sentences as well as the more scientifically accurate sentences.

Duration: Approximately 30 minutes

Project: Units for Sale! Measurement Design Challenge

Students invent an original system of measurement in this design challenge, and then present it to their peers. The fictional setting of a farmstand illustrates the efficiency of standardizing units for liquid and dry measurements. Students consider how unit terminology goes in and out of fashion and the arbitrary nature of selecting units. Then they design a new system of measurement. Students produce a poster to present their system to the class. The whole class discusses and evaluates each system according to given criteria to determine the most effective system. Students end by writing why the highest-rated group earned its high ratings.

Duration: Approximately 100 minutes

Writing: The Universal United Unit Union

Students compose an argument in speech form for or against the idea of a unified standard system of measurement, including examples of how this system would benefit (or have a negative impact on) science, sports, and business. Finally, students consider whether Americans should convert to the metric system by examining the debate over metrication in the United States in a timeline covering 1799 to the present.

Duration: Approximately 45 minutes

Teacher Tune-ups

• Units of measurements: an overview
• Converting Units
• How is mass different from weight?

Student View of Visuals and Activities

Some teachers prefer to have students view the slides and other visual assets in this unit directly instead of projecting them in class. Below is a web page to share with students with links to the same items within in the teacher lesson plans, but without the explanatory text for the teacher.

 

• Student Links to Unit U1 Slides and Other Visuals

Original SciGen Unit

This unit has been adapted from "7.1 So what exactly is a unit?" in the Word Generation program led by Catherine Snow (Harvard University) through a SERP collaboration with the Boston Public Schools and other districts in Massachusetts and Maryland.

PDFs of that earlier unit's teacher and student editions are available at the Science Generation Download Center.

mass

noun – a measure of the quantity of matter in an object

Imagine you take a trip to the moon on a new spaceship. Would your mass change when you leave Earth?

weight

noun – a measure of mass by using an object’s downward force

Does your weight change during a roller coaster ride?

volume

noun – the amount of space taken up by an object

Is it easier to determine the volume of a brick or a stone?

capacity

noun – the amount an object can contain

The capacity of soda bottles is how much liquid they can contain. But the capacity of elevators is how much weight they can hold. What’s the difference?

length

noun – a measure of the longer side of an object; a measure of an object from end to end

A football field is 100 yards long. What do you estimate is the length of your schoolyard?

distance

noun – the measurement between two points

What do you think is the greatest distance you could run without needing to stop and catch your breath?

standard

noun – an idea or thing used to measure

If there were no standard weights, how would we buy food at the grocery store?

unit

noun – a particular quantity that is used to count or measure other quantities

In the U.S. we purchase gasoline using the gallon as the unit of measurement, but most other countries use the liter. What are some other examples of U.S. units that are not used in other countries?