Finding A Marble's Volume
This short activity introduces the concept of volume.
I ask students to sequence events to learn and practice science process skills such as measuring and communicating. When students measure, they use numbers to describe objects like when calculating the volume of an object. Communicating is a way to share the steps taken in a process such as when students sequence events. Student groups share ideas by talking, listening, labeling, and calculating, and then begin to understand that math is another way to communicate in science.
With peers, students read a short paragraph on the worksheet Finding A Marble's Volume which describes how to find the volume of an irregular solid like a marble. I encourage students to look for clue words such as first, next, and then, that signal sequence and then, with their peers, fill in the steps in the concept map to show the sequence of events for measuring and finding the volume of a marble. This KEY provides details on the sequencing strategy.
What happens to the bathwater level when you step into or out of the bathtub?
By asking this question, students engage in the next part of the lesson. This question sparks other questions (SP#1) and creates a dialogue. I ask students to Turn and Talk with their partner(s) to discuss and share their ideas. Then I take 2 minutes so students can share with the class. To engage all students in the dialogue, I use popsicle sticks to draw student names. This provides opportunity for all student to share and the strategy becomes part of the culture of the class.
Some answers to this question include:
How can you find the volume of an irregular solid?
I want student to explore the concept of finding the volume of an irregular solid, so I provide supplies and ask them to read, measure, and calculate with their partner(s). By using these skills students use (SP#5) mathematics and computational thinking.
I circulate the classroom during the inquiry process to ensure that all students are on target, understand how to make the calculations, and work collaboratively with their partner(s).
This lesson focuses on a variety of CCSS math practices including (MP#1) making sense of problems where students understand the problem, find a way to attack it and work until it is done. Students (MP#5) use appropriate tools strategically like a graduated cylinder and (MP#6) attend to precision as they accurately measure water and calculate the volume of a solid. The lesson directs students to (MP#4) model with mathematics as they solve real world problems like volume, organize data during the mathematics calculations, and understand the world around them.
Why is water displaced when the marble is placed in the water?
This question gets students thinking back to the bathtub question in the engage section. I ask this question so that students will make a connection between a bathtub and the marble in the graduated cylinder. This question is also a way to follow up and assess if students did make a connection and requires them to describe their thinking through writing.
A student response that should correlate with this thinking is: "Water is displaced because the marble has mass and takes up space."
How could you adjust this inquiry (investigation) to measure the volume of a solid that floats in water?
This question provide one more opportunity for students to discuss their thinking. The question extends or "stretches" student thinking and requires them to think beyond what they observed in the lesson. By discussing this question with their partner(s), students will come to a better conclusion about the inquiry.
Now, let's write a conclusion. As with any inquiry, sometimes students get it right and sometimes they don't, but that ok. This provides opportunity to discuss what went right, what went wrong, and changes that could be made. This step is very important for students to "come full circle."
I have learned that you need to take students back to the question so they can think about the process. How can you find the volume of an irregular solid? Take 1-2 minutes for students to process the question and write a conclusion. I provide a sentence starter to help with the process, for example: I learned that . . .because. . . Take 1-2 minutes to share answers with the class so students can hear other student thoughts. It's best practice!
Some student conclusions include: