Measuring Liquid Volume
Lesson 4 of 11
Objective: SWBAT read a graduated cylinder and correctly measure a liquid using a graduated cylinder.
Introducing Liquid Volume
This lesson addresses (SP5 Using Mathematics and Computational Thinking) by training students how to measure liquid volume, an important skill in the science classroom and 3.MD.A-2 (students using standard units of measure for volume) is also introduced in this lesson.
I like to start by asking student what the definition of matter is. This enables them to see that matter must have mass AND take up space. I ask them to then define volume and how it can be measured.
The most common response that students share is that volume is length x width x height. This is true for how to solve rectangular prism volume but is not a definition. I want students to realize that volume is simply the amount of space that an object takes up, and that there are many ways to measure volume, depending on the object.
Reading a Graduated Cylinder
I start by showing students how to read a graduated cylinder before actually using them in class. I give out How to Read a Graduated Cylinder Student Worksheet and Reading Scales Worksheet and we practice reading cylinders. We then review as a class.
Before letting students measure with the cylinders, I model their proper use. I emphasize the following guidelines:
- Always measure on a flat surface
- Use the "peace sign" method to hold the graduated cylinder at the base, not on the cylinder itself. This allows the reader to still see the graduations.
- Pour a little bit of the liquid in at a time so as not to go over the line.
- Measure at eye level, reading at the meniscus.
Using a Graduated Cylinder
I break students into 6 groups, 3 groups per side. During this activity, students exchange cylinders with the 3 groups on their side of the room. I have 2 graduated cylinders for each group, including 10 mL, 25 mL and 100 mL models.
I instruct students to give their partner a volume to measure. The partner then pours that volume and the other partner checks the accuracy of their measurement. They then switch roles and repeat the steps until the time frame, about 5 minutes, is up.
After that time, groups pass their graduated cylinders to another group so that everyone gets an opportunity measuring with different graduations.
I leave about 3 minutes for clean up and wrap up. In the wrap up we discuss the importance of knowing the value of each graduation on different cylinders. If students don't know the value of each line then they will not measure accurately.