We suggest students work in pairs. Homeschool students can work on their own, but they will need to make two models so that they can compare and contrast what happens when using the thin versus thick rubber band.

Prepare the Classroom Space

Student pairs will need to set up two Twist-O-Matic models next to each other for easier comparison between the thin and thick rubber bands. Each model takes up the space of about one student desk, so it is easiest if student pairs are sitting next to one another.

NOTE: If you want to make Bumper Coasters with foam tubing, you can view the previous version of this lesson.

This activity works best when students work in groups of 4. Homeschool students can work on their own, but will need to build all four pieces of their roller coaster track.

Make Sure You Have Enough Space

Each roller coaster extends about 1.2 meters (a little over 4 feet) from the box, stack of books, wall, or other surface that it’s attached to. Each group of students will need this amount of space to work through the activity. If you don’t have enough floor space, a few student desks pushed together with a stack of books on top should work.

Prepare Stickers

Cut enough stickers so that you have two for each group of students that will build a roller coaster. The stickers need to be no wider than 2 centimeters so that they can fit and adhere to the roller coaster track.

Decide Where to Store Your Tracks

If you will be teaching Bumper Coasters Part II (Lesson 3), then you must save the tracks and the alligator that each group makes in this lesson. Each set can be stored as pictured below and measures about 82 cm x 8 cm (32” x 3”). We show you how to deconstruct your bumper coaster in this step.

Estimate Your Time Needs

This entire lesson with the activity will take about an hour or slightly more. There are two natural stopping points during the activity ⁠— the first one when students finish building their roller coaster tracks and a second one after they complete their first set of experiments. If you are pressed for time or have a short class period, we recommend splitting this lesson into shorter sessions that might work better for you.

Teacher Tip

Experimenting with marbles is fun, but it can also be distracting! We recommend waiting to distribute the marbles and worksheets until after students have built all of their roller coaster tracks.

We suggest students work in pairs.

Make Sure You Have Space

We suggest doing this activity on the floor. If Bumper Jumper is played on a table the marbles may roll far away if they fall off the table.

We suggest building the Bumper Jumper apparatus where it will be used. Moving the apparatus can affect the connections and how marbles travel. If the Bumper Jumper must be moved after assembly, do so carefully.

Plan Your Time

This entire lesson with the activity will likely take more than an hour. There are two natural stopping points during the activity ⁠— the first one when students finish building their Bumper Jumper apparatus (after step 11) and a second one after they complete their first set of experiments (after step 22). If you are pressed for time or have a short class period, we recommend splitting this lesson into shorter sessions that might work better for you.

Marble Must-Haves

We strongly recommend using “regular” size marbles (14 mm).

IMPORTANT: All marbles used by a group must be the same size/weight. If two different size/weight marbles are used, the results of the Bumper Jumper game will be significantly altered.

Prep Your Materials

Count out 5 full-length label stickers for each pair of students. Then cut the rest of the label stickers in half. Each pair of students will need 5 half-length label stickers. If label stickers aren’t sticking well enough, Scotch tape can be used instead.

Take half of the Dixie cups and place 4 marbles into each one. Distribute these during Step 12 of the activity.

Cut or tear aluminum foil into a small (about 5" x 3") piece. Distribute one piece to each pair of students in Step 23 of the activity.

We suggest students work in pairs. Homeschool students can work on their own, but will need a partner to help with some steps.

Plan Ahead

We strongly recommend pairing this lesson with Lesson 5, “Can you build a chain reaction machine?” If you plan to do Lesson 5, don’t throw away the ramps that your students build in this lesson. Students will use these ramps when creating their very own chain reaction machine.

Classroom Management Tip

Marbles are very fun, but can be very distracting! We suggest waiting to distribute marbles to students until Step 17 of the activity.

We suggest students work in pairs. Homeschool students can work on their own.

Plan Ahead

To complete this lesson, students will need the ramps and levers they built in the previous lesson.

Students can also add a variety of materials to extend their chain-reaction machines. You can ask them to bring things in, or gather some basic materials to keep in the classroom. See the list below for items we recommend having on hand. Or, for more ideas, watch "Inspiration for Chain Reaction Builders" in Extensions before you start this activity to see some possibilities.

• Extra printouts of the “Chain-Reaction Starter Kit” handout from the previous lesson (in case students want to make more ramps)
• Card stock for making custom-built ramps
• Paper cups to serve as ramp supports
• Books and boxes to add height
• Dominoes or objects that will topple like dominoes (dominoes built of LEGO bricks, cassette tapes, paperback books, markers standing on end, etc.)
• String
• More stickers
• Things that roll (empty cans, toy cars, rubber balls, markers lying down, toilet-paper tubes)
• Unconventional ramps (like empty binders)

Make Sure You Have Enough Space

Each Chain Reaction Machine will take up several feet. Each student or group of students will need a table or several desks pushed together as a work space.

Classroom Management Tip

Marbles are very fun, but can be very distracting! We suggest waiting to distribute marbles to students until Step 14 of the activity.