6th grade · Math · Unit 8 of 17
Volume & Capacity
Cubes, liters and milliliters
What your child practices
Finding the volume of rectangular prisms, converting between liters and milliliters, and connecting volume to capacity (1 cm³ holds 1 mL).
Alabama Course of Study content standard: 6.28 · volume of right rectangular prisms
How we explain it
Children can open this short lesson before they practice.
- Volume is the space inside a solid, in cubic units like cm³.
- Volume of a rectangular prism = length × width × height.
- 1 cm³ holds 1 mL. 1000 mL is 1 L.
Example: A box is 5 cm long, 4 cm wide and 3 cm high. What is its volume? 5 × 4 = 20. 20 × 3 = 60. Answer: 60 cm³
Volume & Capacity in Alabama
In the Alabama Course of Study, this is unit 8 of 17 in 6th grade Math, after Perimeter & Area and before Integers & Decimals.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
A box has a volume of 60 cm³. It is 10 cm long and 3 cm wide. How high is it?
answer boxcm
2 cm
Hint: Volume = length × width × height. The base is 10 × 3 = 30 cm², so divide the volume by 30.
Question 2
Which unit is best for measuring a spoonful of medicine?
- kilograms (kg)
- milliliters (mL)
- meters (m)
- liters (L)
milliliters (mL)
Hint: A spoon holds a tiny amount of liquid, so use a small capacity unit.
Question 3
This is the bottom layer of a box packed with 1 cm cubes. The box is 6 layers high. What is the volume of the box?
🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊🧊answer boxcm³
144 cm³
Hint: Find the number of cubes in one layer (rows × columns), then multiply by the number of layers.
Question 4
A fish tank is 10 cm long, 30 cm wide and 25 cm high. 1 cm³ holds 1 mL. How many liters of water does the full tank hold?
answer boxL
7.5 L
Hint: Find the volume in cm³, which equals the capacity in mL. Then divide by 1000 to change mL to liters.
Question 5
A jug holds 2.1 L of lemonade. How many 300 mL glasses can it fill?
🍋2.1 Lanswer box
7
Hint: Change liters to milliliters (× 1000), then divide by 300.
Question 6
A rectangular prism is 12 cm long, 5 cm wide and 3 cm high. What is its volume?
answer boxcm³
180 cm³
Hint: Volume = length × width × height. Multiply two of the numbers first, then multiply by the third.