STEM in the Gym Makey Makey and Scratch Challenge

Want to do more than play banana pianos? What about inventing a game that makes others get active? Try this STEM in the gym challenge and build your invention skills!

Introduction to the Challenge


This Genius Hour project is based on Round Hill PE's super awesome Makey Makey "STEM in the Gym" project. (See Eric's ideas for STEM in the Gym here.) We created this guide to challenge students to create your own physical activity projects with Makey Makey and Scratch. Each day is based on a 45 minute class period. For this guide, we worked with students who were able to work on projects during Genius Hour time and the whole project took about 2 weeks from start to finish that is including teaching time and free work time.

You'll want to make copies (digital or physical) of this student Google Doc to work through your ideas about physical activities you can augment with Makey Makey inventions!

Introduce the problem:

Problem: Video games are sedentary. How might we design a game to get kids to be more active?

Here are some solutions to spark your own thinking: Some examples of physical game solutions with Scratch and Makey Makey:


How would you define prototyping? Write your answer in your Google doc and discuss with a partner how Makey Makey combined with Scratch might be a quick prototyping tool!



Day 1: Introduce Makey Makey

Explore and Play

If you haven't used a Makey Makey yet, you should have a piano day! Hook up Makey Makey to lots of different materials and use different piano apps to learn how Makey Makey works with keyboard presses. 

You can use any app, webpage, or Scratch project that works with key presses. 

Here are a few to try: 

A piano designed for Makey Makey. Play a melody with the arrow keys and space bar (and click, too).

A sampling synth made by Eric Rosenbaum for Makey Makey. Record your own sound, use preset scales, and set the keys to play just the notes you want. 

Scratch Piano
This is a piano you can play with the arrow keys. It was created using Scratch, an easy-to-use graphical programming language, so you can remix it and make your own version.

Chamber Music Piano
You can play 10 different notes on this piano (using w, a, s, d, f, left, up, right, down and space). Play along with the video for a piano duet!


This downloadable app is great if you just want to drag and drop sounds onto keys on a keyboard, then press the keys to play them. Try it with the example keymap we made with drum and marimba sounds for mac or windows.

Sketch it! Play it!

After experimenting with different materials, make a playable pencil drawing. Your drawings must have separate connections and each separate drawing will be conductive and function as a different key press! Hook up your drawings to your favorite piano app. (See the full guide for drawing your own instrument here.)


Day 2: Make a Switch and Learn Scratch

Simple Switches

Create a simple momentary switch with foil and cardboard, and hook it up to Makey Makey and control it with Scratch. 

Getting Started with Scratch

If you've never worked with Scratch or Makey Makey before, check out this Googledoc or this Guide for Coding Key Presses with Scratch to get started!

Day 3: Teach Scoring and Timers

Scoring Variables

Learn how to make a scoring variable in Scratch. Full code is available in the student GoogleDoc.

Creating a Scoring Variable in Scratch

Create variables for scoring and timer in the variable palette. You’ll set the score to zero with the < WHEN [flag] clicked> block. You’ll want to assign the score to change on a key press. You can alter the variable for different key presses depending on your challenge! You may need a <WAIT _ SECONDS> block to keep players from pressing and holding on your switch and scoring too quickly!



A timer can help get other kids active in your game. (Timer instructions are also in this student GoogleDoc.)

You can create a timer quickly with the block by changing your timer variable by 1 every second. If you want to make a 60 second relay game, where players switch halfway through the game, you can add this code:

WHEN [flag] clicked

SET [timer] to [60]

SHOW variable [timer]


REPEAT until [timer] = [30]


WAIT [1] seconds

SAY [Change player!] for [2] seconds


REPEAT until[timer] = [0]


WAIT [1] seconds

SAY [Time is up!] for [2] seconds

Brainstorming and Drafting

Think about how you might combine switches and scoring to create a few different project ideas. Could you make a low jump/high jump scoring game? A jumping jack counter game? Spend some time tinkering with scoring and timer codes in Scratch. Brainstorm your project ideas with someone and make sure to sketch out your project ideas!


Build Your Game

It might take a few days to put together your project idea. Our students worked on this project in their "Genius Hour" time for a week or so before they were ready to share their projects with PE classes.

When you are finished with your project, write a "Rules and Expectations" poster to be placed by your game when you are ready to share it!


Share your Project

Share your hard work and let others play your game.

Check out the games created by some awesome elementary students in this video!




    Time Investment
    2 hours




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