This activity is perfect for cross-curricular work with ELA.  Learning to write effective is invaluable in many fields, not just science.

After the primary lesson students can extrapolate to real life devices and how they store energy to perform work.

For a an extension to this activity students could drop the ball from three predetermined heights, record the height of the first bounce, and then predict the height of the first bounce for a fourth starting height.

Students can get excited about using some simple measurement techniques to accomplish something big.  Working in heterogeneous ability groups would help students whose math ability is lower contribute without feeling inadequate.

If I were to do this activity I would instead give the students a set of materials that they can use and have groups compete to use the same materials to design the best marshmallow launcher.  Before beginning, talk to students about strategies for solving this type of problem, such as sketching a plan of the design.

One final thought, advanced student might enjoy learning about the formulas of projectile motion.

Make sure to emphasize the need to keep careful records as that is what makes this activity appropriate for teaching the Nature of Science.  This activity is excellent for showing children the value of records as it utilizes information from 50 years ago.  Discovering patterns and trends is also very appropriate in this area of study.  Creating a presentation of the information would offer a chance to incorporate different multiple intelligences.

Increase the critical thinking skills needed for this activity and connect it to ELA standards by requiring students to write why a hovercraft would or would not be an effective form of mass transportation based on their design experiences.

The number of different properties that the teacher requires the students to observe can greatly affect the difficulty of this assignment.  That offers a great opportunity for differentiation.  This would probably be best as a long activity during a detailed unit.

Make sure to add taking measurements in metric units to this activity in order to fully meet the standard.  This unit could be connected to a social studies unit on the plants that are important to the local community and humans in general.

Student who are ready can learn to read a thermometer or a barometer as well as a part of this activity.  Make sure to encourage careful record keeping and not accurate predictions.  Students should be made aware that one does not "win" science by making correct predictions.

While this activity does not cover a specific standard it does meet the requirement of teaching the design process.  Make sure that students must design, test, and revise their design to make the activity authentic.  A race would be a great final activity.  Assessment could come from an oral presentation on what they did and why or a visual presentation, such as a poster.

This experiment can lead nicely into a social studies unit about the importance of water to human communities.  It could also be used as a starting point for a discussion of how scarcity affects price.

Students with high literacy skills can read more information about worms and share it with the class.  Students with low literacy skills can be in charge of making drawings of their observations to keep a visual record of the worms' progress.

I like this activity because it works well for a wide variety of students.  For students who are easily overwhelmed reduce the number of scents to match.  High level students could be asked to come up with an idea for another experiment like this one but for a different sense.  Consider allergies when you plan this activity!

Students who finish early could try drawing the structures of blood.  If the teacher can obtain the materials, looking through a microscope at real slides of blood and draw that for a further extension.

The math in this activity is not too challenging but it requires the students to be precise in their data collection to see good results.  It meets the goals of the CCSS for 6th grade math that students "Attend to precision" and "look for and make use of structure".  Gifted students might be interested in the information about the Buffon Needle Problem, link found in the "Tips" section.  To extend the lesson students could consider what changes could be made to the lesson to improve the accuracy of its approximation of pi.

This lesson offers a great chance to work with a writing lesson.  Students can learn how the wording of their questions might affect the answers they receive.  This could then spawn another lesson in critical thinking about how real surveys done by groups might be biased to their preconceived ideas.  Working in groups would allow students of various ability levels and learning styles to all contribute to the group.

Larger coordinate planes could be used for longer games.  Make sure to have the players compare their two graphs at the end, if they are different someone made a mistake.

This activity has a natural connection to a science lesson about how our senses and nerves work to create reactions.  The teacher can require different forms of data analysis based on the students' skill level.  Simple min/max to averages and standard deviation are available.

Adjusting the vocabulary that is required allows a teacher to differentiate this activity.  After completing the dictionary in addition to studying at home students can quiz each other for review in a co-op structure such as "Quiz-Quiz-Trade".