Invent a Chain Reaction Contraption

by dave_littlebits

Published on March 8, 2016

Students will brainstorm ideas and then use the littleBits Invention Cycle to perform a simple task with a chain reaction contraption inspired by Rube Goldberg. Students will use defined constraints and criteria for success to test and then iterate upon their 2+ step contraption to improve its functionality. Conclude the activity by having students create videos of their chain reaction contraption in action.

By the end of the Lesson, students will be able to:
  • Brainstorm ideas for meeting the designated challenge
  • Create and test a circuit containing a power source, inputs and outputs
  • Construct a prototype of an invention that using Bits and other materials
  • Test their prototypes and make improvements
  • Self-assess their work based on the identified success criteria and constraints
  • Demonstrate their ability to CREATE, PLAY, REMIX and SHARE an invention through the littleBits INVENTION CYCLE by recording their processes in the Invention Log
  • Summarize their process and share the resulting invention by creating a “before” and “after” storyboard.


BITS: any Bits

OTHER MATERIALS: See list of commonly used materials on pg. 119 of the STEAM Student Set

ACCESSORIES: any accessories

TOOLS USED: See list of commonly used tools on pg. 119 of the STEAM Student Set

The Invention Log checklist (pg.18) can be used to assess your students’ understanding of the Invention Cycle, use of the Invention Log and ability to attain the objectives of the lesson. For formative assessment while students work, you can use this checklist to ask questions about their current task and ensure that they are on the right track. The checklist can also be used as a self-assessment tool by students as they move from phase to phase. For summative assessment, you can use this checklist to review students’ entries into their Invention Log and assess their understanding of the challenge and the invention process as a whole.


3-5-ETS1-1 Engineering Design: Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost.
  • To fulfill this standard, students are explicit about the need or want being designed for, and call it such, as well as criteria for success and constraints of materials, time, cost etc. that they’re willing to work within.
3-5-ETS1-2 Engineering Design: Generate and compare multiple possible solutions to problem based on how well each is likely to meet the criteria and constraints of the problem.
  • To fulfill this standard, students explicitly compare multiple solutions on the basis of the success and criteria constraints.
3-5-ETS1-3 Engineering Design: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.
  • To fulfill this standard, students test their prototypes and make improvements. Set all but one variable as fixed, and change just one parameter in attempts to maximize the agreed upon criterion for success. Students may also be allowed to “borrow” the best aspects from one another’s designs during this process.
MS-ETS1-1 Engineering Design: Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.
  • To fulfill this standard, students set various criteria for success, as well as constraints for the successful completion of the design problem.
MS-ETS1-2 Engineering Design: Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.
  • To fulfill this standard, students Create different solutions to the problem and explicitly compare them on the basis of their ability to meet the goal within constraints.
MS-ETS1-3 Engineering Design: Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solutions to better meet the criteria for success.
  • To fulfill this standard, students test their prototypes and make improvements. Set all but one variable as fixed, and change the amount of just one parameter in attempts to maximize the agreed upon criterion for success. Students may also be allowed to “borrow” the best aspects from one another’s designs during this process.
To meet these standards, students will need to fill out information in the REMIX section of the Invention Log (pg.11 and 12) every time a variable is changed and tested. Be sure to print additional copies of these pages before the lesson begins.

*For other curricular connections, see the“Extension” section at the end of this lesson.

littleBits Invention Log

For Open Challenges, we recommend that the teacher Create an example invention themselves, which may or may not be shown to students at the beginning of the lesson. Taking the challenge through the Invention Cycle will better equip teachers to successfully conduct the lesson and be more knowledgeable about where the class, or specific students, may need a bit more time or support.

power, output, input, circuits, magnetism, criteria for success, constraints

  • Introducing littleBits
  • Introducing the Invention Cycle


    Rube Goldberg Cartoon Gallery (

    Six Rube Goldberg Machines (

    OK Go Rube Goldberg Machine (

  • Duration: 120 minutes (minimum) *For tips on how to break up your lesson over multiple class periods, see pg. 117 of the STEAM Student Set Teacher’s Guide

    Lesson Guide


    SET UP

    This lesson can be done individually or in small groups (2- 3 students). -For an advanced challenge, have the whole class collaborate to invent a massive contraption!

    Each group will need at least one STEAM Student Set and Invention Guide, plus one Invention Log and Assessment Checklist per student. We suggest handing out the Bits in the Create phase to keep students focused on initial instructions and review activities. For more experienced users, you may want to provide access to additional Bits in the Play and Remix phases to provide a greater diversity of circuit combinations. Place a variety of construction materials and tools in a central location in the room.


    INTRODUCE (15–20 MIN)

    Introduce the lesson objectives and the concept behind the challenge:

    “Rube Goldberg was a cartoonist who liked to draw really complicated solutions to very simple problems. For example, to turn the page of a book, you might roll a ball down a ramp that hits a box. Then the box falls over and scares a hamster that starts running on its wheel, that winds up a string that turns the page. In this challenge, you’re going to design your own multistep machines. Before you start inventing, there are two important rules: 1) Once you start your machine, it needs to be able to run without any help from you. Each step must be triggered automatically by the step before it, and 2) Your machine should have at least two steps (bonus points if you can Create more!)”

    Share videos and/or cartoons of Rube Goldberg machines to provide context and inspiration.

    Most design challenges focus on how life can be made easier by an invention. This challenge is a fun exploration in the opposite direction. How complicated can we make a very simple task? To this end, you may want in favor of a little absurdity and whimsy.

    Before jumping into the challenge, provide a quick review of the Invention Cycle framework and the format of the Invention Log (pg. 35 of the STEAM Student Set Teacher’s Guide). Ask students to Share lessons learned about Bits, the invention process and things they enjoyed or struggled with from previous challenges.


    CREATE (45–55 MIN)

    For each of the prompt sections below, students will record their process and reflections in their respective Invention Logs.

    What ideas do you have? Prompt students to Create a list (either as a class, or in groups) of everyday activities that only take one step. For example, dropping a can in the recycling bin, flipping on a light switch or opening a book. For brainstorming tips, refer to pg. 36 of the STEAM Student Set Teacher’s Guide.

    Which idea seems best? After making a list of 5- 10 ideas, have students choose the everyday activity that they want to accomplish. It could be the idea that sounds the most fun to solve or is the most accessible in the classroom.

    Students should frame their thinking in the following framework: I will invent a_______that______because_____.

    What’s the “before” story? What is life like now, before the proposed invention exists? Ask students to draw or describe the series of events before, during and after to show cause-and-effect scenarios. Be sure to consider the characters involved and the setting that the “story” takes place in.

    What are the constraints? Constraints are the limits and requirements that need to be considered in the invention process. Examples include time, materials, weight. Have students detail any constraints that they may need to keep in mind as they work. For younger students, you may choose to run this exercise as a class and have students record shared ideas.

    What are the criteria for success? How will students know if their invention works? Describe the #1 goal for the invention. What qualities are important for the invention to have?

    7ba4086a 61fe 4860 bfe2 69f73315a8cf



    PLAY (10–15 MIN)

    How did your testing go?

    Once the prototypes have been constructed, students should test the steps of their contraption to see if it works. Getting all of the moving pieces to work together is going to be a challenge; failure is part of the process. Encourage students to try running the contraption a few times, doing initial adjustments on angles, connections and materials. Students should take note of successes and things that still need to be improved in their Invention Logs.

    D5db59b9 6db8 41a4 9183 e6f1658a5baf



    REMIX (15–25 MIN)

    To meet the outlined NGSS standards, instruct students to fill out a new Remix section in their Invention Logs (pg. 11 and 12) every time a variable is changed and tested. If you are do not plan to adhere to the NGSS standards, allow students more flexibility and exploratory pathways during this phase of the design process.


    This is the opportunity to experiment with fixes and improvements. As students make changes to their inventions, make sure they are documenting in their Invention Logs how their prototypes are changing and the results (good and bad).

    If students need some inspiration, set the invention aside and look through the remaining Bits and available materials. Is it possible to complete a step with them? Try a few options and see how they compare to what has already been created.

    Continue the Remix phase (and remind students to Play with their updated inventions) until the prototype is able to meet the criteria for success, or until the allotted time runs out. If you need more advice on how to conduct and provide prompts in the Remix phase, read through the Invention Advisor section (p. 36 of the STEAM Student Set Teacher’s Guide).

    16c4ffe6 7794 49bd 822b c6fc0ccf4ec9



    SHARE (30–35 MIN)

    Wrap up the challenge by reflecting and tying together the story of the invention. Have students take a video of the contraption in action and post it to your favorite social media channel or the littleBits website.

    As an alternative, students can Create their own Rube Goldberg cartoons to describe what their invention is used for and how it works.

    706a93d8 ea70 4e0b 8663 f195c3dd200a



    CLOSE (5 MIN)

    At the end of the lesson, students should put away the Bits according to the diagram on the back of the Invention Guide, clean up their materials and hand in their Invention Logs.



    Incorporate one (or more!) of the following extensions in the Remix section of this challenge to bolster your lesson’s NGSS applications:

    MS-ETS1-4 Engineering Design: Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved.

    - To fulfill this standard, students define and iteratively collect data to explore the explicit connection between the invention and a physical or environmental interaction that may impact the design. For example, modeling the impact of friction on the ability of a wheeled invention to climb a slope, or the impact of an invention on human behavior. The storyboard in the Invention Log should be used and updated throughout the lesson for each iteration tested.