Mass Measurement Examples in Math

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Mass Measurement.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Math.

Concept Recap

Mass measurement determines how much matter an object contains, using standard units such as grams and kilograms.

Mass tells you how heavy something feels — a paperclip is about 1 gram, a textbook is about 1 kilogram.

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How to Use These Examples

Read the first worked example with the solution open so the structure is clear.
Try the practice problems before revealing each solution.
Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: Mass measurement tells how heavy an object is in grams and kilograms, where $1$ kg $= 1000$ g.

Common stuck point: The procedure for mass measurement is the easy part; the trap is mixing grams and kilograms when converting. Asking "Am I measuring how much matter (how heavy) an object is, rather than the space it fills or how long it is?" first is what keeps a correct-looking calculation from being attached to the wrong concept.

Sense of Study hint: Ask: Am I measuring how much matter (how heavy) an object is, rather than the space it fills or how long it is?

Worked Examples

Example 1

medium

A box of

12

cans has total mass

4.2

kg. What is the mass of one can in g?

Answer

350\text{ g}

First step

Convert:

4.2

= 4200

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Example 2

medium

A balance scale has

750

g on one side. You add

250

g and a mystery object to balance

2

kg on the other side. What is the object's mass?

Example 3

medium

A scale reads

1.23

kg. A pack of butter is

250

g. After adding the butter, what does the scale read in kg?

Example 4

hard

A metal cube is

5

cm on a side and has density

7

g/cm

^3

. What is its mass in kg?

Example 5

hard

Two materials are combined:

200

^3

of A (density

3

g/cm

^3

) and

100

^3

of B (density

5

g/cm

^3

). What is the total mass in kg?

Example 6

hard

A boat carries

1.5

tonnes of cargo. If each crate is

75

kg, how many crates does the boat carry?

Example 7

challenge

1

kg gold bar is melted and recast into

10

identical coins. If

1

kg of gold has volume about

51.8

^3

, what is each coin's volume in cm

^3

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

easy

Which unit best measures the mass of an apple?

Example 2

easy

True or false: a

1

kg bag of feathers weighs the same as

1

kg of rocks.

Example 3

easy

Which is heavier:

800

g or

1

kg?

Example 4

easy

An elephant weighs about

5

tonnes. How many kg is that?

Example 5

easy

A loaf of bread is

450

g. Two loaves weigh how many g?

Example 6

medium

A bag of apples is

2.5

kg. After removing one

150

g apple, what is the new mass in g?

Example 7

medium

Three packages weigh

1.2

kg,

750

g, and

1.05

kg. Find total in kg.

Example 8

medium

A baker uses

1.8

kg of flour daily. How many g per week (

7

days)?

Example 9

medium

8

identical cookies weigh

200

g. What's the mass of one cookie?

Example 10

medium

A child's mass is

32

kg. The recommended dose is

15

mg per kg of body mass. What dose in g?

Example 11

medium

A box weighs

5

kg empty. Filled, it weighs

12.3

kg. What is the contents' mass in g?

Example 12

medium

A truck can carry

2

tonnes. How many

50

kg sacks can it carry?

Example 13

hard

A mixture of

300

g sugar in

700

g water has what percent sugar by mass?

Example 14

hard

An astronaut's mass on Earth is

70

kg. On the Moon (gravity

1/6

of Earth's), what is the astronaut's mass?

Example 15

hard

Five boxes have masses (kg):

4.2, 5.1, 3.8, 4.5, 4.9

. What is the average mass in g?

Example 16

hard

A scale is accurate to

\pm 5

g. It reads

325

g. Give the range of true mass.

Example 17

hard

A solid has volume

0.5

L and density

1.2

g/mL. What is its mass in kg?

Example 18

hard

If a

2

kg melon costs $3.50, what is the price per kg?

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Related Concepts

Comparison Multiplication Unit Rate

Background Knowledge

These ideas may be useful before you work through the harder examples.

comparisonmultiplication