ScienceGrade 3

How Do Scientists Measure Mass? Balance Scale Challenge

Mass means how much stuff (matter) is inside something — not how big it looks.

Learning Objective

Students will learn that mass is the amount of matter — "stuff" — inside an object, that a balance scale measures mass by comparing two objects until the beam is level, and that size does not predict mass: a big puffy object can lose to a small dense one (TEKS 3.6A — measure, test, and record physical properties of matter, including mass).

What You'll Learn

A balance scale compares two masses: the heavier side dips, the lighter side rises,
We measure mass in units like grams — a paperclip is about one gram.
Big does not always mean more mass — a giant pile of feathers can lose to a little
Your mass is the same everywhere — the Moon, Mars, the playground — because the

Words to Know

Mass: How much stuff is inside an object.; The marble has more mass than the feather pile.
Matter: The stuff everything is made of — anything that has mass and takes up space.; Feathers, marbles, and you are all made of matter.
Balance scale: A tool that compares two masses — it dips toward the heavier side and sits level when they match.; The balance scale's marble side dips down.
Gram: A unit for measuring mass — about one paperclip.; The pencil has a mass of about twelve grams.
Level: Perfectly flat and even — on a balance it means equal mass.; The beam sits level when both sides match.

Check What You Learned

Quick Quiz

1 / 5

Mass means how much WHAT is inside a thing?

Fun Facts

Mass is the amount of matter ("stuff") in an object; matter is anything that has mass and takes up space
Source: NGSS 5-PS1-1; standard elementary physical-science definitions
A balance scale compares the masses of two objects: the side with more mass dips down, the lighter side rises, and a level beam means the two masses are equal
Source: standard physical-science curricula / equal-arm balance principle
Scientists measure mass in grams and kilograms; a standard metal paperclip has a mass of about 1 gram, making it the classic classroom benchmark
Source: NIST / metric benchmarks used in elementary curricula
Size does not determine mass: a large fluffy object (feathers, foam) can have less mass than a small dense object (a metal marble) because mass depends on how much matter is packed inside, not on the space taken up
Source: standard matter/density concept, NGSS 5-PS1-3
Mass is a property of the matter itself and does not change with shape, place, or squishing — a flattened clay ball keeps its mass, and your mass is the same on the Moon as on Earth
Source: conservation of matter / standard physical-science curricula
Balance scales are among the oldest scientific instruments — ancient Egyptians used balance-beam scales to weigh grain and gold roughly 5,000 years ago
Source: history of metrology, widely documented

Lesson Info

Grade 3

Standards Alignment

TEKS 3.6A
measure, test, and record physical properties of matter, including temperature, mass, magnetism, and the ability to sink or float
5-PS1-1
matter is made of particles too small to be seen; measurements of properties identify materials
Math tie-in (TEKS 3.7A math)
solve problems involving mass measurement in grams/kilograms