Volume seems to be a confusing concept to middle schoolers. Because the word itself has multiple meanings; because there are several "close confuser concepts" such as mass and area; and because of the mathematical component, the concept of volume deserves some concerted developmental time.
Since many of the Next Generation Science Standards for Physical Science rely on a basic understanding of matter and what it is, volume becomes a fundamental concept for understanding the more complex core disciplinary ideas (DCI) within the standards, especially the Matter and Its Interactions DCI (MS-PS1). Since an understanding of matter is so basic to physics and chemistry, understanding volume as a requirement for matter is necessary (Do I Matter? Introduction to Matter).
This understanding of matter is also related to the exploration of several crosscutting concepts such as Structure and Function; Energy and Matter: Flows, Cycles and Conservation; and Scale, Proportion and Quantity. These crosscutting concepts suggest that matter is made of stuff and we have to be able to identify, describe and quantify that "stuff" in order to make sense of the world around us. Additionally, making accurate and precise measurements is a student need when planning and carrying out successful investigations (SP3).
In order to ENGAGE students in this lesson, listen to the THX Surround Sound Test. Ask students to listen for and be able to describe how the sound changes.
Students generate and share ideas. Once they suggest the idea of volume, press them to explain what volume means in this scenario. Students will be able to explain that volume is the how loud or soft a sound is. Ask them:
When a sound is loud do you think about it as a small or big sound?
Follow up with:
Does a big sound really take up more space?
Ask student to view this video and think about how it shows the idea of taking up space:
Students share a few ideas with the class. The most common response is that the balloon takes up more space when it is blown up like a loud noise seems to fill a space. When this idea surfaces, the important teaching move here is to clearly delineate between the concepts of sound volume and physical volume.
Sound volume is the magnitude or intensity of a certain sound. Physical volume is a property of matter that refers to how much space a three-dimensional object takes up. When the discussion arrives at this definition, have students write it down on the Measurement Volume Student Handout.
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 concept of volume, students use a variety of resources in small groups to complete various investigations on the Measurement Volume Student Handout in order to find the volume of different objects in three different ways:
1) Calculate the volume of solid cubes or rectangular prism objects using a formula.
2) Measure the volume of liquids using a graduated cylinder.
3) Develop a procedure to calculate the volume of oddly shaped objects.
While students EXPLORE, they will need support clarifying their understanding and practicing with the tools of measurement. During this time, rotate through groups to ask students probing questions about the concepts, so they can EXPLAIN their understanding. The questions may range in Bloom's Revised Taxonomy complexity from "remember" type questions such as: "What is the tool called we use to measure volume?" to "create" questions such as, "If you wanted to teach a student how to use the graduated cylinder, what would you need to include in your teaching notes?" An example of a student's response to this prompt can be viewed here:
As students advance through the EXPLORE and EXPLAIN stages of the lesson, it is imperative to provide a short direct instruction lesson about how to read a graduated cylinder or beaker safely and accurately. This mini-lesson can be conducted table-by-table or with the whole class. Students need to see and hear the process being modeled or they oftentimes make assumptions about how to use the tool (which results in misuse and inaccurate use). Videos are helpful for previewing the concept but do not replace the direct modeling by an expert and lots of student practice.
During the third investigation (Develop a procedure to calculate the volume of oddly shaped objects), there are instructions for students to view a "demonstration". In the past, I've done an elaborate portrayal of Archimedes' famous "eureka" moment in which I wear a crown and get into a garbage can filled with water. Alternate possibilities to this full submersion (six times in a day!) are smaller demonstrations using toys that cause water in a beaker to overflow or video:
When groups finish, we review the Measurement Volume Student Handout together. I model for students how to neatly complete the activity and we briefly discuss each topic as we review. This stage of the lesson presents a great place for a quick formative assessment because students are able to explain their answers and ask questions about parts of the activity they don't yet understand. When we finish reviewing, I offer students a clean copy of the notes: Measurement Volume Student Handout Notes.
The materials needed for these investigations include:
1) Small plastic cubes like these: Centimeter Cubes; 2) Wooden blocks; 3) Graduated cylinders and beakers; 4) Various oddly shaped objects; 5) Plastic droppers
Measuring Volume Presentation (ScienceSpot) can be used to introduce the basics of volume.
The EXTEND stage allows students to apply new knowledge to a novel situation. For students who move through the activities quickly, I check their work and give them the choice to:
1) Review the concepts by making flashcards, quizzing or reading additional sections from the textbook.
The EVALUATION stage is for both students and teachers to determine how much learning and understanding has taken place. The primary way I evaluate student learning is by giving students an assessment that focuses on the "remember", "understand" and "apply" levels of understanding: Measurement Volume Basic Quiz or Measurement Volume Checkout Quiz. By reviewing student work: Measurement Volume Student Work, it is also possible to identify glitches in understanding.