Lesson 7

In previous lessons, students measured and estimated the weight of objects in grams and kilograms. In this lesson, students learn that liquid volume is the amount of space that a liquid takes up and consider the challenges of directly comparing liquid volumes by just looking at them. Students use informal units (such as plastic cups, spoons, and so on) to compare the liquid volume that two containers will hold. Finally, students are introduced to the liter as a metric unit of liquid volume. They create a tool for measuring liquid volume in liters by filling a container and making a mark for each liter as it’s added to the container. A clear container is used so students can see the level of the liquid and a dry erase marker is used so the marks can be erased after the lesson.

To build a conceptual understanding of liquid volume, it is extremely helpful for students to have firsthand experience of comparing liquids in different containers. To make that possible, some new materials and preparation are required for this lesson.

Activity 2: Volumen líquido, en litros

Each group of 4 needs:

• a supply of water (1 liter bottles would work and could be reused for the next activity)
• two containers that are different in shape, but close in size, each labeled with “A” and “B”
• a small container labeled with “unit,” such as a large spoon, film canister, or a small measuring cup
• a tray or towel to work on (optional)

Gather the following materials:

• a large clear container that can be written on, such as a gallon water jug with top removed or clear storage bin
• 1-liter container (1-liter water bottle, measuring cup, etc.)
• a supply of water (enough to fill the larger container)
• OR the Liquid Volume in Liters video: https://vimeo.com/451620298