5.MD.4: Measuring Volume by Counting Cubes

Visual Models for Measuring Volume by Counting

1. Building with Standard Units: Use centimeter cubes or inch cubes to build various rectangular prisms. Count the total number of cubes used and state the volume in the correct cubic units (e.g., "24 cubic centimeters").

2. Using Improvised Units: Build the same shape using non-standard units like sugar cubes or identical small blocks. Count these units to find the volume in terms of that improvised unit (e.g., "18 sugar cubes"). Discuss why standard units are important for communication.

3. Drawings with Labeled Units: Use isometric drawings of prisms made of cubes. Label the side length of one cube (e.g., 1 cm). Have your child count the cubes and state the volume in cubic centimeters.

4. Comparing Volumes: Build two different shapes using the same type of unit cube. Count the cubes in each to determine which shape has a larger volume.

Everyday Activities

1. Packing Challenge: Give your child a small box and a collection of identical items (like sugar cubes, dice, or small blocks). Ask them to figure out how many items (unit cubes) fit inside the box to measure its volume.

2. Estimating Volume: Look at different boxes (cereal box, tissue box). Estimate how many inch cubes might fit inside each. Discuss the approximate volume in cubic inches.

3. Building Volume: Use building blocks (Legos, wooden cubes) and challenge your child to build a structure with a specific volume, like "Build a tower with a volume of 30 blocks."

4. Sandbox Volume: Use a small container (like a yogurt cup) as an improvised unit. Count how many scoops (units) of sand are needed to fill a larger bucket. This demonstrates measuring volume with non-standard units.

Strategies When Your Child Struggles

1. Reinforce Unit Definition: Ensure your child understands what "cubic cm," "cubic in," etc., mean – a cube with sides of that length. Use physical examples.

2. Systematic Counting: Teach methods like counting layers or columns to ensure all cubes (including hidden ones) are counted accurately.

3. Use Physical Models: If drawings are confusing, always go back to building with physical cubes. Count them together.

4. Label Units Consistently: Remind your child to always include the unit when stating the volume (e.g., "12 cubic inches," not just "12").

5. Differentiate Standard vs. Improvised: Discuss why standard units (cm³, in³, ft³) are useful for everyone to understand the size, while improvised units (sugar cubes, blocks) are only useful if everyone knows the size of the unit.

5-Minute Activities

Activity 1: Picture Volume: Show a drawing of a prism made of unit cubes (specify the unit, e.g., cubic cm). Ask your child to find the volume by counting.

Activity 2: Build and Count: Give your child a handful of unit cubes. Ask them to build any rectangular prism, then count the cubes to find its volume.

Activity 3: Unit Check: Show a shape built with cubes. Ask, "If each cube is 1 cubic inch, what is the volume? What if each cube is 1 cubic centimeter?"

Activity 4: Volume Match: Build two different shapes. Ask your child to count the cubes in each and determine if they have the same volume.

Mid-Year Expectations

By the middle of 5th grade, your child should be able to:

• Count unit cubes (including hidden ones) to find the volume of rectangular prisms.
• State the volume using the correct standard cubic units (cm³, in³, ft³) when given.
• Measure volume using improvised units (e.g., blocks, sugar cubes).

End-of-Year Expectations

By the end of 5th grade, your child should be able to:

• Fluently measure the volume of rectangular prisms by counting unit cubes.
• Consistently use appropriate standard cubic units.
• Understand the difference between standard and improvised units for volume.
• Connect counting cubes to the volume formula (V = l × w × h).

Mastery Signs

Your child has mastered this standard when they can consistently:

• Accurately count unit cubes in models or drawings to find volume.
• Use correct units (cm³, in³, ft³, or improvised units) when stating volume.
• Explain how to find volume by counting cubes.
• Apply cube counting to find volumes in simple real-world contexts.

Questions to Ask:

Ask your child these questions to check their understanding:

• How many cubic centimeters are in this shape? (Show a model/drawing made of cm cubes).
• How many sugar cubes would fit in this box? What is the volume in sugar cubes?
• Why is it important to say "cubic inches" instead of just "inches" when talking about volume?
• How can you make sure you count all the cubes, even the ones you can't see?

Below Grade Level

Practice counting visible cubes in simple structures and using one type of unit cube.

📥 Download Practice Worksheet

At Grade Level

Standard practice counting unit cubes (including hidden ones) using various standard and improvised units.

📥 Download Grade Level Worksheet

Above Grade Level

Challenges involving finding the volume of composite shapes by counting cubes and problems requiring conversion between cubic units (extension).

📥 Download Challenge Worksheet