SME
Grade 3 Math · Problem type
Compare masses
Use this for “The dog is 23 kg and the cat 5 kg. How much heavier is the dog?”
Diagram
The heavier mass is 18 kg more.
This is an example. Type your own values to start a new problem.
Heavier mass (kg)
−
Lighter mass (kg)
=
How much heavier (kg)
Formulas
23 − 5 = 18
Heavier mass − lighter mass = how much heavier
Assumptions
•
Both masses must use the same unit.
•
Take the lighter mass away from the heavier one.
Step-by-step
WE KNOW
Heavier mass: 23 kg
Lighter mass: 5 kg
FIND
how much heavier
Step 1 · Find how much heavier
23 − 5 = ?
Heavier mass − lighter mass = how much heavier
Take the lighter mass away from the heavier mass.
23 − 3 = 20
20 − 2 = 18
How much heavier = 18 kg
Check
Put the numbers back in. Both sides should match.
23 − 5 = 18 ✓
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