Once the students have entered the room, I give them a note card containing a word or phrase that is a type of quantitative measurement, a measurement tool, or a unit of measure. The students try to find members of their group based on determining the types of tools and units used for specific types of measurement. For instance, one card has the word time, so the other cards that go with the group include clock and minutes.
The students have previously completed this activity in the lesson Basic Processes - Exploring the Flip, but I use the activity periodically because as a strategy it gets students thinking, and it gets students up and moving. Once the students have found their group members, I ask them to jot down a list of at least five examples of items that can be measured using their unit of measurement. Once all of the groups have had an opportunity to write down some answers, I call on each group asking them to share their list. The rest of the class is tasked with double checking their answers to make sure that the items mentioned can be measured using the tools and units assigned to the group.
I then ask the students to remind me of the ways that we can find the mass and volume for a variety of items. To this point, the students have had difficulty articulating the various methods for determining the volume of different items. Since we reviewed finding mass using the triple beam balance on the previous day and given their difficulty with determining the volume of objects, I lead a quick review of volume. This review is primarily me asking questions about volume and the students providing answers rather than me simply telling the students how to conduct the measurements. I have found that tasking the students with sharing the information makes the information more meaningful to the rest of the class because the students all know that they may be called on to give the information and I think the pitch of the voices of their peers helps the students remember the information rather than hearing the pitch of my voice constantly.
During this conversation, I ask a student to model finding the volume of a tissue box. I ask another student to find the volume of the can of soda on my desk (the can is not full, so they cannot simply read the side of the can). A third student is tasked with finding the volume of sugar. As the students complete these tasks, their activities are directed by their classmates and only one help or instruction can be given by each student, meaning that most, if not all, of the students are involved in the activity. I also take time to ask the students to explain what a meniscus is and we review the type of meniscus created when water is placed in a graduated cylinder. We also discuss why the meniscus is created in this fashion. In a previous set of notes we reviewed the difference between the meniscus of water in a glass graduated cylinder and that of mercury.
The students meet up with their lab partner and complete the mass and volume lab worksheet. This worksheet is designed to have students think about the various steps involved in determining the volume of various items as well as the steps required to use a triple beam balance.
In the previous class session, the students finished the front of the lab sheet. Their goal for the day is to finish the measurement portion of the activity. While the students are working on the activity, I circulate through the lab observing their measuring techniques and asking them questions about the measurements they are performing. As I circulate through the room, I also remind the students not to place the sand into wet graduated cylinders. In this video I provide additional suggestions for conducting this activity.
Engaging students in measurement practices, especially calculating volume, which requires the use of a math formula addresses SP5 - Using Mathematics and Computational Thinking - which states that Mathematical and computational thinking in 6–8 builds on K–5 experiences and progresses to identifying patterns in large data sets and using mathematical concepts to support explanations and arguments. This exercise also helps students develop the skill necessary to
Use mathematical representations to describe and/or support scientific conclusions and design solutions.
Create algorithms (a series of ordered steps) to solve a problem.
Apply mathematical concepts and/or processes (e.g., ratio, rate, percent, basic operations, simple algebra) to scientific and engineering questions and problems.
To wrap up the lesson, I ask the students to share some of their answers from the discussion questions at the end of the lab. I focus in on the question regarding the use of volume and mass in the real world. I begin by having a partner-set turn to another partner-set and share their thoughts. I then have those partner-sets turn to the table behind or in front of them and again share their thoughts. Having the students turn and talk provides them with a more comfortable space to share their ideas and affords each student the opportunity to share. By having the students complete this more than once, they are able to hear multiple perspectives and are able to refine their own thoughts as they share their information again. After the students have shared within their small groups, I call the class back together and ask for volunteers to share the various ways that we use volume and mass on a regular basis outside the classroom.