Reveal Math Grade 3, Unit 9: Liquid Volume and Mass
In this unit, your child measures and estimates liquid volume in liters and mass in grams and kilograms. Children read scales and measuring containers carefully and solve word problems with those amounts. It uses the scales from the graphs unit just before it and closes the year by measuring the real things around them, from a bottle of water to a bag of rice.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Unit 9?
- Estimating and measuring liquid volume in liters and mass in grams and kilograms, and solving one-step word problems with those measurements. Learn more: Weighing things and measuring liquids
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
The green tub holds 12 liters of water. The blue tub holds 7 liters. How many more liters does the green tub hold than the blue tub?
- 19 liters
- 15 liters
- 5 liters
How you can help
- Hold a 1-kilogram bag of rice in one hand and a small packet in the other, read both labels, and talk about how 1,000 grams make a kilogram.
- Fill a 1-liter bottle with water at the sink and pour it into a pot or bowl, counting how many liters it takes to fill.
- Weigh fruit on a store scale and ask your child to guess first: will 4 apples be closer to 1 kilogram or to 5 kilograms?
Where kids can get stuck
- Assuming a bigger object always has more mass, so an empty cereal box seems heavier than a can of beans.
- Reading a measuring container at an angle or skipping what each mark stands for, so the amount is read wrong.
- Adding when a problem calls for multiplying, so 3 bottles of 2 liters each comes out as 5 liters instead of 6.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- liquid volume
- How much liquid a container holds, measured in liters.
- liter
- A unit of liquid volume; a large water bottle holds about 1 liter.
- mass
- How heavy something is, measured in grams or kilograms.
- gram
- A small unit of mass; a paper clip is about 1 gram.
- kilogram
- A unit of mass equal to 1,000 grams; a big dictionary is about 1 kilogram.
- scale
- The numbers along a graph's side, or the marks on a measuring tool.
- estimate
- A close guess, often made by rounding, to check whether an answer makes sense.
Ready to build your child’s confidence with mass and liquid volume?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
Join the club
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does Reveal Math Grade 3 Unit 9 cover?
Reveal Math Grade 3 Unit 9 covers this math standard. Each one links to what it means, sample questions, and teaching strategies.
- 3.MD.A.2: Estimate and measure in grams, kilograms, and liters.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.