Grade 3 · Measurement & Data · MAT-03-MD-003
Measure and Estimate Mass
Represent measure and estimate mass with words, symbols, diagrams, or models appropriate to Grade 3.
Learning objectives
What you should be able to do
- Represent measure and estimate mass with words, symbols, diagrams, or models appropriate to Grade 3.
- Solve problems involving measure and estimate mass accurately and explain why the method works.
- Check results for reasonableness using a second representation, inverse relationship, benchmark, or property when appropriate.
Prerequisite check
Make sure the foundation is ready.
Checks conceptual readiness before new Grade 3 reasoning.
Checks whether prior skills are available for use, not only recalled by name.
Learn
Build the idea from meaning, not memorization.
Meaning of Measure and Estimate Mass
Mass describes how much matter an object contains and is measured in grams and kilograms at this level.
A reliable reasoning strategy
Choose grams for lighter objects and kilograms for heavier objects, then estimate before measuring.
Representations that should agree
Benchmarks such as a paper clip near a gram or a large textbook near a kilogram support sensible estimates. A correct model, equation, verbal explanation, or diagram should preserve the same quantities and relationships.
How to check the result
Check whether the answer fits the quantities, units, and structure of the problem. Use a second representation or inverse relationship when available, and explain what would make an answer unreasonable.
Math Box · Interactive lesson
Touch the math. Change it. See what stays true.
Use the interactive model before and after the worked examples. Change the inputs, make a prediction, then use the model to test whether your reasoning holds.
Number Line Explorer
Move along the number line.
4 is one less. 5 and 6 is one more.
- build a model
- change one quantity
- predict before calculating
- explain why the result changes
Worked examples
Twenty different ways to see the concept work.
A pencil has a mass of about 7 grams. Which unit is appropriate?
7 gGrams are suitable for light classroom objects.
A textbook has a mass of about 900 grams. Which unit is appropriate?
900 gA book can reasonably be measured in grams when it is less than a kilogram.
A backpack has a mass of about 4 kilograms. Which unit is appropriate?
4 kgKilograms are appropriate for heavier objects carried by a person.
A bicycle has a mass of about 12 kilograms. Which unit is appropriate?
12 kgA bicycle is much heavier than objects usually measured in a few grams.
Which is more reasonable for an apple: 180 g or 180 kg?
180 gAn apple's mass is measured in hundreds of grams, not hundreds of kilograms.
Which is more reasonable for a chair: 5 g or 5 kg?
5 kgA chair is far too heavy to have a mass of only five grams.
A bag of rice has a mass of 2 kg and another has a mass of 3 kg. What is the total mass?
2 kg + 3 kg = 5 kgAdd masses expressed in the same unit.
A 9 kg box has 4 kg removed. What mass remains?
9 kg − 4 kg = 5 kgSubtraction finds the remaining mass.
Three identical packages each have a mass of 2 kg. What is their combined mass?
3 × 2 kg = 6 kgEqual masses can be combined with multiplication.
A balance shows 500 g on one side and a toy on the other side is balanced. What is the toy's mass?
500 gA balanced scale indicates equal mass.
A bag has a mass of 750 g. A second bag has a mass of 250 g. How much heavier is the first?
750 g − 250 g = 500 gDifference in mass is found by subtraction.
A 1 kg package and a 3 kg package are shipped together. What is their total mass?
1 kg + 3 kg = 4 kgBoth measurements use kilograms, so add directly.
Estimate the better mass for a paper clip: 1 g or 1 kg.
1 gA paper clip is a very light object.
Estimate the better mass for a watermelon: 4 g or 4 kg.
4 kgA watermelon is thousands of grams, so kilograms are more sensible.
A scale reads 325 g for a bowl and 475 g for a plate. What is the combined mass?
325 g + 475 g = 800 gAdding the two gram measurements gives the combined mass.
A container originally has 950 g of material. After 300 g is used, how much remains?
950 g − 300 g = 650 gSubtract the used mass from the starting mass.
Two objects have masses 600 g and 590 g. Which is heavier and by how much?
600 g is heavier by 10 g.Compare the values and subtract 590 from 600.
A dog has a mass of about 18 kilograms. Would 18 grams be reasonable?
No; 18 kg is reasonable.Grams would be far too small a unit for the mass of a dog.
A recipe needs 200 g of one ingredient and 350 g of another. What total mass is measured?
200 g + 350 g = 550 gThe ingredient masses use the same unit and can be added.
Why should a mass estimate include a unit?
A number alone does not tell the measurement scale.7 g and 7 kg describe very different masses, so the unit is part of the measurement.
Practice
Guided practice with hints
01A classroom object has a mass of about 575 grams. Which unit is appropriate for recording this measurement?
Hint: Choose grams for lighter objects and kilograms for heavier objects, then estimate before measuring.
Answer: grams
02A classroom object has a mass of about 650 grams. Which unit is appropriate for recording this measurement?
Hint: Choose grams for lighter objects and kilograms for heavier objects, then estimate before measuring.
Answer: grams
03A classroom object has a mass of about 725 grams. Which unit is appropriate for recording this measurement?
Hint: Choose grams for lighter objects and kilograms for heavier objects, then estimate before measuring.
Answer: grams
04A classroom object has a mass of about 800 grams. Which unit is appropriate for recording this measurement?
Hint: Choose grams for lighter objects and kilograms for heavier objects, then estimate before measuring.
Answer: grams
05A classroom object has a mass of about 875 grams. Which unit is appropriate for recording this measurement?
Hint: Choose grams for lighter objects and kilograms for heavier objects, then estimate before measuring.
Answer: grams
06A classroom object has a mass of about 50 grams. Which unit is appropriate for recording this measurement?
Hint: Choose grams for lighter objects and kilograms for heavier objects, then estimate before measuring.
Answer: grams
Practice
Independent practice
01A classroom object has a mass of about 275 grams. Which unit is appropriate for recording this measurement?
Answer: grams
02A classroom object has a mass of about 350 grams. Which unit is appropriate for recording this measurement?
Answer: grams
03A classroom object has a mass of about 425 grams. Which unit is appropriate for recording this measurement?
Answer: grams
04A classroom object has a mass of about 500 grams. Which unit is appropriate for recording this measurement?
Answer: grams
05A classroom object has a mass of about 575 grams. Which unit is appropriate for recording this measurement?
Answer: grams
06A classroom object has a mass of about 650 grams. Which unit is appropriate for recording this measurement?
Answer: grams
07A classroom object has a mass of about 725 grams. Which unit is appropriate for recording this measurement?
Answer: grams
08A classroom object has a mass of about 800 grams. Which unit is appropriate for recording this measurement?
Answer: grams
Common mistakes
Learn to catch the error, not just the answer.
Compare the object with a familiar benchmark before selecting a unit.
Reconnect the answer to measure and estimate mass and verify that the model, calculation, and label describe the same quantity.
Applications & challenge
Use the idea beyond a single exercise.
Applications
- Estimate and compare the mass of classroom and household objects.
- Use measure and estimate mass to interpret or solve a Grade 3 situation with quantities, diagrams, measurements, or data.
Challenge problems
A classroom object has a mass of about 875 grams. Which unit is appropriate for recording this measurement?
grams
A classroom object has a mass of about 50 grams. Which unit is appropriate for recording this measurement?
grams
A classroom object has a mass of about 125 grams. Which unit is appropriate for recording this measurement?
grams
A classroom object has a mass of about 200 grams. Which unit is appropriate for recording this measurement?
grams
Flashcards
Retrieve it from memory.
Flashcards
Card 1 of 4
Game mode
Measure and Estimate Mass Challenge
Solve and explain Grade 3 problems involving measure and estimate mass without relying on answer guessing.
Practice
Mastery check
01A classroom object has a mass of about 575 grams. Which unit is appropriate for recording this measurement?
Answer: grams
02A classroom object has a mass of about 650 grams. Which unit is appropriate for recording this measurement?
Answer: grams
03A classroom object has a mass of about 725 grams. Which unit is appropriate for recording this measurement?
Answer: grams
04A classroom object has a mass of about 800 grams. Which unit is appropriate for recording this measurement?
Answer: grams
05A classroom object has a mass of about 875 grams. Which unit is appropriate for recording this measurement?
Answer: grams
06A classroom object has a mass of about 50 grams. Which unit is appropriate for recording this measurement?
Answer: grams
07A classroom object has a mass of about 125 grams. Which unit is appropriate for recording this measurement?
Answer: grams
08A classroom object has a mass of about 200 grams. Which unit is appropriate for recording this measurement?
Answer: grams
Terminology
Words to know
- gram
- A metric unit for relatively small masses.
- kilogram
- A metric unit equal to 1000 grams.
Continue learning
Connected concepts
Curriculum references
Standards and instructional references
California Common Core State Standards for Mathematics — Grade 3, 3.MD.2
Primary standards alignment for Measure and Estimate Mass.2023 Mathematics Framework for California Public Schools
Instructional emphasis on reasoning, representations, problem solving, and equitable access.