U2 Day 17: Lesson Resources

Code.org resources and space to share your resources

unit 2 day 17.pdf (157.7 KB)

LessonU2-17.pdf (390.6 KB)

Here is my unit 2 Lesson along with the activity.

Minimal Spanning Tree Worksheet.docx (14.8 KB)

Lesson plan

I agree with your comment in your notes, that is why when I did this activity I had my students look up the traveling salesman problem and they began to see how this topic better relates to a realistic problem.

Unit2ChallengeLesson.pdf (99.6 KB)

Here are some great resources I’ve found from other teachers and some I’ve made myself for U2 Day 17:

Muddy City Activity handout - https://docs.google.com/document/d/14Wc-NVLwBKk329evm4sSPJLnoWDwshAnT_GUWhN27Dg/edit?usp=sharing

Why UPS Drivers Never Turn Left video link - https://www.youtube.com/watch?v=HV_bJxkdNDE&index=33&list=PLHbgghOimk-hFtTpAprJrZ69fEvaucqtJ

Mythbusters - Right Turn Only MiniMyth video link - https://www.youtube.com/watch?v=ppCz4f1L9iU&index=34&list=PLHbgghOimk-hFtTpAprJrZ69fEvaucqtJ

Why UPS Trucks Don’t Make Left Turns video link - https://www.youtube.com/watch?v=ppCz4f1L9iU&index=34&list=PLHbgghOimk-hFtTpAprJrZ69fEvaucqtJ


Carol Guerin
Extension Activity

Day 17 The Minimal Spanning Trees-Muddy City

First I would have the students break up into teams of 3 or 4 each and present them with the challenge. Together they must come up with the most economical solution for paving the roads in Muddy City.

Second I would have them use Plastic Placemats for the paving stones(each team would have different colored “paving stones”) and the Desks in the classroom would be used to represent the houses. This would make the solution more interactive and hands on.

Each team would present their solution to the Muddy City Problem using the placements and desks to show the route they intended to use. Teams would then walk their route through the roads in Muddy City. Counting out their steps between houses and noting the number of paving stones required. It would get everyone up and moving.

As an alternative you could use an old style Twister mat and dry markers to map at the routes for each team.


These are some excellent resources, I love the UPS drivers never making a left. The USPS could use some help in that department.

I love the idea of twister or even a transparent shower curtain and dry erase markers.

Love the idea of the shower curtain and dry erase markers as welcome lets them get their artistic juices flowing.

An extension activity I would use in my class is have the students placed at random places around the room. I would then use yarn to connect the students to each other. This example could be shown with the longest route first, just so students get the idea and then do it the shortest route. Students could do this also instead of the teacher. This activity is great for those students who need to get up and moving and it also gives students a chance to collaborate with each other. You could even include challenges to it by moving students each time or not allowing them to talk to each other.


Great idea - it’s always important to keep moving and figure out ways to “embody” the computer science concepts to reach all types of learners.


  • Used Memeo board to produce a larger view of Muddy City map.
  • Students came up to board and drew their map version.
  • Some great Aha! moments.

I love using interactive boards to get students engaged and talking through their project. Have the students try out their plan and revise as they go.

The interactive board is also fun when you get started in Scratch and the students can help move the blocks around to program their Sprites.

I love the idea of the clear shower curtain.

One of the major problems for students is how to get from their core classes to my room or to gym which are both at the opposite side of the building from core classes and language classes. This often results in students being a few minutes late to my class for the first couple of weeks and for some students, it may take up to a month to find their way. Because of this, as an extension activity, I’m creating a map for students to use to calculate the quickest, most direct path from specific classes to my classroom. I can also split the class into teams and hand each team a pedometer to have them start from specific points in the school, follow a path (different for each team) to my room and see which team can get there with the least number of steps.


I really like the idea to create the map for the quickest route, or most direct route with the least number of steps. What a way to apply the problem solving process in a way that they can relate to other areas of their life.