3rd Grade · Measurement & Data
3.MD.A.2: Estimate and measure in grams, kilograms, and liters
3.MD.A.2 is a 3rd grade Common Core math standard in Measurement & Data. Here’s what it really covers, and how you can help your students learn it.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
The standard
Measure and estimate liquid volumes and masses of objects using standard units of grams (g), kilograms (kg), and liters (l). Add, subtract, multiply, or divide to solve one-step word problems involving masses or volumes that are given in the same units, e.g., by using drawings (such as a beaker with a measurement scale) to represent the problem.
In plain words
Estimate and measure in grams, kilograms, and liters.
Sample questions from student practice
These questions from Bobby's Math Club are the kinds of questions your students will see. You can try answering them to see what a student might see.
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
Where students can get stuck
- Picking the wrong unit for an estimate, such as saying an apple weighs about 200 kilograms.
- Assuming a bigger object is always heavier, so a large pillow must outweigh a small rock.
- Reading a scale or container at the wrong line, such as viewing the liquid at an angle or skipping what each mark stands for.
Effective teaching strategies
- Let students hold a bag of crumpled paper and a small rock, predict which is heavier, and check on a balance, so they see that size does not decide weight.
- Give students a 1-gram and a 1-kilogram benchmark to hold, such as a paper clip and a liter bottle of water, and estimate other items against them.
- Have students read scales and containers at eye level, and say what each mark stands for before they read the measurement.
Units that teach this standard
Find where 3.MD.A.2 lands in the program you teach. Each unit has a guide written for families. Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence.
Bridges in Mathematics
enVision Mathematics
Everyday Mathematics
i-Ready Classroom Mathematics
Illustrative Mathematics
Math Expressions
Reveal Math
Don’t see your curriculum? Contact Bobby and we’ll see if we can help!
Share it with families
Families can read Weighing things and measuring liquids for a plain-language look at this skill, with three questions to try together and ideas for helping at home.
Help every student practice measurement and data at home
In Bobby's Math Club, students practice 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 for every family.
See how it works for teachers
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.