Mass and Weight
Lily and Grandpa George follow a gold medal from Earth to the Moon, Jupiter, and Pluto, discovering that its mass remains 1 kilogram while its weight changes with each place’s gravitational pull. A glossary then defines mass, weight, matter, gravity, Newton, kilogram, and force.
About the Book
Lily and Grandpa George follow a gold medal from Earth to the Moon, Jupiter, and Pluto, discovering that its mass remains 1 kilogram while its weight changes with each place’s gravitational pull. A glossary then defines mass, weight, matter, gravity, Newton, kilogram, and force.
Prerequisite Requirements
Readers benefit from noticing that objects can feel heavier or lighter and from recognizing simple numbers and units. No formal science preparation is necessary; the story builds the distinction between mass and weight from familiar situations.
Learning Benefits
This book creates opportunities to compare measurements across locations, observe which property stays constant, connect gravity with how heavy an object feels, and use scientific vocabulary in conversation. Its repeated medal readings support pattern finding, prediction, and shared rereading.
Structured Knowledge Path
The book sits within introductory physical science, linking matter and measurement with gravity and force. It provides a foundation for later ideas about mass versus weight, gravitational fields, measurement units, and how the same object behaves in different environments.
Advancement
The distinction between a stable amount of matter and a changing gravitational force can support later study of force, motion, planetary science, and measurement. Comparing the medal’s readings also develops transferable habits of tracking variables, using evidence, and explaining cause and effect.
Knowledge Points
- Mass describes the amount of matter in an object and stays the same when the object moves between planets.
- Weight is the force of gravity acting on an object’s mass, so it can differ from place to place.
- The medal has the same mass on Earth and the Moon even though its weight changes.
- A planet’s gravitational pull affects how heavy the medal is.
- Mass and weight use different measurement units: kilograms for mass and Newtons for weight.
Vocabulary
- mass
- The amount of matter in an object; in the story, the medal’s mass is 1 kilogram wherever it travels.
- weight
- The force of gravity pulling on an object’s mass.
- matter
- The material that makes up objects, such as the gold atoms in the medal.
- gravity
- The force that pulls objects toward the center of a planet.
- Newton
- The unit used to measure weight, which is a force.
- kilogram
- The unit used to measure mass.
- force
- A push or a pull.
Reading Guidance for Teachers and Guardians
- Page 3: Pause at the medal’s two readings and ask what the kilogram measures and what the 9.8 Newtons measures.
- Page 5: Invite the child to look closely at the gold atoms and explain why the amount of matter is called mass.
- Page 6: Compare the Moon’s 1.6 Newtons with Earth’s 9.8 Newtons and wonder what could make the reading smaller.
- Page 9: Notice that Jupiter changes the medal’s weight to 25 Newtons without changing its mass.
- Page 11: Ask the child to put Earth, the Moon, Jupiter, and Pluto in order from greatest to least weight based on the story.
- Page 12: Reread Lily’s conclusion and invite the child to explain the difference between what the medal is made of and how strongly a planet pulls it.
- Page 14: Use the glossary to revisit any word that helped explain the medal’s journey.