Participants will crack the code using teamwork, rational thinking, and the process of elimination to
successfully mimic computer codes. This activity pairs versatile body movement with rational
thinking to create dynamic challenges for participants as they learn about the importance of
computational thinking in the digital world.
This activity was developed by Actua’s Outreach Team for the 2019 camp season.
To Do in Advance
- Assemble supplies for all sections.
- Divide plastic straws and connectors into sets of 14 straws and 10 connectors per pair.
- Draw out an example 4×4 grid for Section 2 with a few patterns of increasing difficulty.
Opening Hook: Robot Languages
Introduce participants to the activity by asking them what robots they know about. Ask
participants if robots can think for themselves? Do they have a brain?
- Robots have computers for brains! These computers control and coordinate the
robot the same way our brain does. However, they require specific instructions in
specific languages. Some robots are able to recognize patterns and update their
code to reflect new knowledge – this is called machine learning, which we see in
Have a facilitator sit or stand in front of the group. Place a piece of paper and a pair of
scissors on a flat surface near them (for example, a table. If there are no tables, the floor is
Tell participants that this facilitator will be our robot today (hereafter referred to as “the
robot”). We want our robot to cut us out a triangle. What instructions can we give it in order
to accomplish that task?
- The robot should do their best to only respond to explicit instructions and is
encouraged to misinterpret them to exemplify how specific instructions need to be. The sillier the robot is, the more fun the activity will be.
In order to be successful, the cut should follow a general outline:
- Define for the robot what scissors, paper, and a triangle are.
- Teach the robot how to hold the scissors.
- Teach the robot how to cut.
- Write a loop to facilitate continuous cutting.
Once the triangle is successfully cut out, discuss with participants what was challenging about the game, what worked well, and ask what they learned about how computers and robots think and learn.
Section 1: Can You Stack It?
- Divide participants into pairs and give each pair t a set 14 straws and 10 connectors.
- Have participants sit back-to-back with their straws and connectors in front of them. This activity will be run twice to give each participant an opportunity to be the programmer and the robot. For the first round, decide who will be who.
- The programmer should begin building their structure, giving the robot instructions on how to build the same structure as they go. The robot can not ask clarifying questions. Give participants 10 minutes to finish building their structures. Ensure robots/programmers are not peeking at the other’s structures.
- Once time is up or the structures are built, allow participants to turn around and see if they
were successful in building exact replicas of each other’s structures.
- Take 1-3 straws away from each participant in order to force them to create a different
structure. Repeat activity.
Section 2: Can You Crack It?
- Have participants help you create a 4×4 grid using the straws and connectors from Section 1.
Squares should be 2 straws x 2 straws to reduce the chances of participants tripping.
- Introduce participants to the idea of an algorithm in the context of computer science. An algorithm is a set of steps a computer takes in order to accomplish a specific task. The steps
have a specific order or reason behind them and have rules and boundaries.
- In this activity, participants will need to be a computer enacting an algorithm to try and crack
the passcode to get into a safe. Inside the safe are passwords needed to save the world – so
it’s extremely important they crack the code as fast as possible.
- Our algorithm will have the following rules and boundaries:
a. We are trying to crack a six-digit password; therefore, only six of the boxes will give
us a positive reaction.
b. All of the boxes (which represent a button on a security pinpad) that are needed for the password are touching each other. When on a “correct” box, participants will only need to step one box away.
c. Have participants stand in a line beginning on the X. The first participant takes a step into the grid and stands in a box they think is the first key that needs to be pressed on the keypad. The instructor will reference their guide and either make a “ding ding” sound or an “errr” sound. Participants waiting in line should be watching to try and remember the sequence. Participants keep stepping through the grid until they get an incorrect guess. Then the next participant hops through the portion of the password that’s been determined until they hit an incorrect guess. This is meant to be fast-paced and participants should cycle through quickly.
d. Here is an example passcode to be cracked:
5. Once the code has been cracked, ask participants investigatory questions about the process.
Was it easy or hard? What were the hard parts? Did you ever forget which ones had already
been chosen? Discuss how computers can use algorithms even faster than we can, because
they never forget anything.
6. Depending on time and participant interest levels, you can run this activity multiple times
with increasingly difficult patterns.
Reflection & Debrief
Reflection & Debrief
- Ask participants what they’ve learned about how computers think. What are some things
that computers might be better than humans at? What are some things they wouldn’t be as
Extensions & Modifications
How might you adapt the time, space, materials, group sizes, or instructions to make this activity
more approachable or more challenging?
- Run any of the activities again with higher stakes – a more complex task for the robot to
complete in the opening hook, more diverse building materials in Section 1, and more
complex/longer passwords in Section 2.
- Have participants work in groups of three in Section 1 with one computer programmer and
two computers so they are able to support each other.
- Instead of having participants line up in Section 2, have them stand around the grid so theycan provide vocal support and guidance to the person attempting to use the algorithm to crack the code.