Grade 3 Measurement: Grams and Kilograms

Measure and estimate mass

What You'll Learn

Choose grams or kilograms for an object
Solve one-step problems with masses in the same unit (3.MD.A.2)

📖Mass

Grams measure light things: a paper clip is about 1 gram. Kilograms measure heavy things: a big book is about 1 kilogram. Add, subtract, multiply or divide masses that use the same unit.

Worked examples

Real problems from the practice worksheets, solved one step at a time.

Example 1
Would you measure the mass of a bicycle in grams or kilograms?
1. Grams are for light things (a paper clip is about 1 gram). Kilograms are for heavy things (a big bottle of water is about 1 kilogram).
2. A bicycle is heavy, so use kilograms.
3. The answer is kilograms.
Answer: kilograms
Example 2
A bag of rice has a mass of 22 kilograms. A bag of flour has a mass of 22 kilograms. What is their total mass in kilograms?
1. Total mass means put the two masses together: add.
2. 22 + 22 = 44.
3. Their total mass is 44 kilograms.
Answer: 44
Example 3
Each bag of sand has a mass of 7 kilograms. What is the total mass of 7 bags in kilograms?
1. 7 equal bags of 7 kilograms each: multiply.
2. 7 × 7 = 49.
3. The 7 bags have a total mass of 49 kilograms.
Answer: 49