7th Grade Computer Science • Class 2

Think for Yourself

Python gives us a place to practice one of the most useful skills you can build: figuring out what to do when nobody has already handed you the next step.

Start the lesson Jump to the Python lab
Our 42 minutes
0–15
Independent CodeHS
15–22
Devil's Bridge
22–32
Think for Yourself
32–39
Why It Matters
39–42
Back to Python
1

Why are we learning Python?

The commands matter. The thinking underneath them matters even more.

Programming turns your thinking into something a computer can test. A computer does not know what you meant. It follows the instructions you actually gave it. That forces you to make your thinking more precise.
💡
1. IdeaWhat do I want?
🧩
2. Break it downWhat are the smaller moves?
🎯
3. PredictWhat do I think will happen?
▶
4. TestRun it. Look closely.
🔁
5. AdjustUse the evidence. Try again.
2

Devil's Bridge — Sedona, Arizona

A real adventure from Mr. Steckler's life — and a story about fear, judgment, taking a chance, and moving in your own way.

Photo from the top of Devil's Bridge in Sedona, Arizona showing Mr. Steckler and his wife sitting on the natural sandstone arch above the red rock landscape.
The real photo from the story. This was taken at Devil's Bridge in Sedona after making it onto the arch in very windy conditions.
Mr. Steckler's story

We made it to the top. Then I had a decision to make.

Devil's Bridge is a huge natural sandstone arch near Sedona, Arizona. You can hike to the top and, if you choose, walk out onto the arch itself.

The day my wife and I reached it, the wind was intense — gusts around 65 mph. My wife was comfortable enough that she was practically skipping across the arch. I wasn't.

I had originally just wanted the photo from the top. When it was my turn, I decided to go farther. I crawled toward the middle. At one point I hit a twig, slipped down onto a small edge, pulled myself back up, kept going, and we got the drone photo.

We did not meet the Devil. We did come home with a pretty great adventure.

A little about me

This story is mostly here because I want you to know your teacher. I was scared, I tried something I had never done before, and it became one of those adventures I still remember.

Now here is the connection to this class. I am not asking you to crawl onto a sandstone arch. I am going to ask you to take smaller risks all year: try code before you know whether it will work, attempt something you have never done before, keep going when your first idea fails, show an unfinished idea, and ask for help when you need it.
Your turn

What can taking a risk look like in Computer Science?

Tap the kinds of risks you are willing to practice this year. There is no single one you have to choose.

3

How do you know something is true?

A correct answer can come from understanding. It can also come from repeating something you trust.

Question 1

Is Earth round?

More precisely, Earth is approximately spherical and slightly flattened at the poles. Choose your answer first.

Question 2

Now remove authority. What evidence could you understand or test?

Click each type of evidence. Notice the difference between trusting a source and understanding evidence.

Try the idea

Eratosthenes' shadow experiment

More than 2,000 years ago, Eratosthenes used shadows, distance, and geometry to estimate Earth's circumference. Move the controls and watch the calculation.

800 km
7.2°
Your estimated Earth circumference
40,000 km
Formula: distance × (360 ÷ angle difference). Earth's equatorial circumference is about 40,075 km.
4

Would the group change your answer?

This mini challenge is inspired by Solomon Asch's classic conformity experiments.

Target line
Which line is the same length?
A
B
C
Before you answer...

Everyone else in your group has already answered:

Student 1: BStudent 2: BStudent 3: BStudent 4: BStudent 5: B

What do you say?

What Asch found In the classic study, the correct line comparison was obvious. Still, 76% of participants conformed to the incorrect group at least once. The point is not that people are unintelligent. The social environment can influence judgment even when the evidence is sitting in front of us.
5

What skill do employers rank #1?

Guess before revealing the data from the World Economic Forum's Future of Jobs Report 2025.

Which of these was most often identified as a core skill for workers?

Analytical thinking
69%
AI & big data
45%
Reading / writing / math
21%
Programming
17%
This is why getting stuck in code can be useful. When nobody tells you the next command, you have to inspect the problem, gather information, test an idea, and decide what to do next. That is analytical thinking in practice.
6

What is this time worth?

A rough way to visualize the public investment behind one school day in White Plains.

White Plains' adopted 2026–27 district budget: about $284.93 million. Using an estimated enrollment of 6,766 students, a 180-day school year, and the regular Highlands day from 7:44 AM to 3:15 PM, we can make a rough district-wide per-student estimate.
$42,112
Per student / year
$234
Per student / school day
$31
Per student / school hour
$22
Per student / 42 min class
25 students → roughly $545 of district-wide spending represented during one 42-minute period.

This is a visualization, not the literal marginal cost of one class. The district budget supports salaries, buildings, technology, transportation, support services, programs, benefits, and many other costs across the school system.

7

Back to Python: make a prediction, then run it

This playground matches Tracy's coordinate world: Tracy starts at (0, 0) in the center, facing east. The world runs from -200 to 200 on both axes.

Mini Turtle program
Supported commands: forward(number), circle(number), left(number), right(number)
Tracy's World
Start: (0, 0)  •  Heading: east  •  Range: -200 to 200
Thinking move: before pressing Run, point to where you think the turtle will end.
Debug this

The computer is not being difficult. It is being exact.

forwad(100)

What is wrong with this command?

8

The habit to practice

You do not have to solve everything alone. Give your brain a real first attempt.

Before you ask me what to do, show me what you tried. That one habit makes your question better and gives us something real to examine together.
When I get stuck...I can look at the evidence before guessing.
When my code fails...I can treat the result as information.
When everyone says one thing...I can still ask, “What supports that answer?”
✓

Sources & further reading

The interactive activities simplify ideas for class discussion. These links support the factual claims on the page.

Class 2 • 7th Grade Computer Science • Interactive lesson companion