Big or Small: Measure It All
Western Reserve Public Media

Video Supplements: Space
How Much Do You Weigh on Other Planets?


Students discuss the difference between mass and weight and find what various weights would be on different planets.


Students will understand the concepts of mass and gravity. They also will practice measurement conversion.


Standards Addressed — Mathematics

Grade 5
Use Measurement Techniques and Tools, Benchmark B

05. Make conversions within the same measurement system while performing computations.





  1. Review the concepts of mass and weight. This explanation is on the student handout:

  2. The mass of an object is a fundamental property of the object; a numerical measure of its inertia; a fundamental measure of the amount of matter in the object.

    The weight of an object is the force of gravity on an object.

    If you had a mass of 100 pounds on earth, your mass would not change on any of the planets. But your weight would change because weight is the result of the pull of gravity. The greater the gravity, the more the object weighs. Each planet has more or less gravity than Earth.

  3. Distribute the student handout and talk about what a person who weighs 100 pounds on Earth would weigh on the other planets. Discuss why this is so. Discussion could lead to the size or density of the planet and the effect on the gravitational pull.

  4. Make sure the students are aware that 1 pound equals 16 ounces.

  5. Have students fill in the Gravity on the Planets graph. Discuss if there is an association between the gravity of the planet and their weight on that planet. (The more gravitational pull, the greater the weight.)

  6. Have the students compute their weight on each planet and convert the pounds to ounces. Don’t give specific directions, such as “multiply by the number given in the table.” Let the students figure out how to do this. The sights listed below will calculate weights on the other planets for you. You can have the students check their work online.

  7. How Much Would You Weigh on Another Planet? —

    What Do You Weigh on Other Planets? —

    Your Weight on Other Worlds

    A word of caution: Some students may be very sensitive about their weight. If this appears to be the case, you could have the students work with a partner and use one of the weights instead of having the students do individual handouts.

  8. Have the students complete the other weight problems.


Answers for Student Handout

  1. 3.15 pounds

  2. 844.6 pounds

  3. 519 pounds

  4. 1.08 pounds

  5. 17.9 pounds


The teacher should work through the first part of the handout with the students. The second part can be checked by the students going online and inputting the weights and comparing them with their answers.
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