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This lesson will guide students through the steps of debugging. Students will learn the mantra: "What happened? What was supposed to happen? What does that tell you?"

Research shows that some students have less trouble debugging a program than writing one when they first learn to code. In this lesson, we introduce the idea of debugging in a real-world sense. The goal in this lesson is to teach students steps to spot a bug and to increase persistence by showing them that it's normal to find mistakes. In later lessons, students will debug actual programs on Code.org.

Note: You will need to create a free account on code.org before you can view this resource.

Computers talk to each other over the internet via messages. However, the internet is not reliable and sometimes these messages get lost. There are certain bits of information we can add to messages to make sure they are sent. This information makes up a protocol.

In this activity, students consider how different methods of communication operate successfully. By looking at rules and procedures in place, students are introduced to communication protocols. By working through a role-play scenario, pupils test their own protocol operating in an unreliable environment similar to that found in packet switching on the Internet, specifically, TCP/ IP.

On the internet, data is broken into packets for transportation. However, the channels in which these packets travel is not always reliable. Individual packets sometimes are damaged, lost or lose their ordering.

In the game Tablets of Stone, tablets are packets and their content is data. Packets contain both data and header information. The size of the header information affects how much data can be transferred – so a balance has to be reached, as packets are of finite size.

Students will find that they will need to swap some of their data boxed for information such as packet number and total packets, or whether or not the packet is an acknowledgment packet. Due to this information taking up data boxes, overall more packets will be needed.

While some people turn to social networks and texting as an opportunity to open up and be themselves, others are looking for targets. In this video segment from FRONTLINE: "Digital Nation," learn about Ryan Halligan, the victim of a vicious cyberbullying campaign. After Ryan committed suicide, his father, John, went on Ryan's computer to search for answers. As Ryan's friends opened up online to John, he learned about the taunting that his son endured both at school and online. This video comes with discussion questions.

In this lesson, students continue learning the concept of loops. Here, Laurel the Adventurer uses loops to collect treasure in open cave spaces. A new get treasure block is introduced to help her on her journey.

This lesson gives students more practice with loops and encourages them to put multiple blocks inside of a repeat< as they try to collect as much treasure as possible.

Students will be able to:
- Identify the benefits of using a loop structure instead of manual repetition.
- Break down a long sequence of instructions into the smallest repeatable sequence possible.

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You may not realize this, but each time you logon to the Internet, use your cell phone, or do anything digitally you are leaving a digital trail. In this Thing you will be completing four Quests. Once you complete these Quests, you will earn the 21t4s Investigator badge.

LEARNING OBJECTIVES

When you have completed this Thing you will:

1. know the concepts and actions that create a digital footprint [Digital Citizen]

2. understand that my digital footprint has an impact on my life [Digital Citizen, Empowered Learner]

3. understand the importance of electronic documentation [Empowered Learner]

4. be able to create a positive and safe online web presence [Innovative Designer, Digital Citizen]

5. be able to collaborate with classmates and work effectively toward a common goal [Global Communicator]

We ended the last episode at the start of the 20th century with special-purpose computing devices such as Herman Hollerith’s tabulating machines. But the scale of human civilization continued to grow, as did the demand for more sophisticated and powerful devices. Soon, these cabinet-sized electro-mechanical computers would grow into room-sized behemoths that were prone to errors. But it was these computers that would help usher in a new era of computation - electronic computing.

In this activity, students will discover ways that scientists and engineers can use rovers to explore places where humans cannot go. Students will construct a science rover using the LEGO WeDo 2.0 kit and program the rover using WeDo 2.0 Software or a compatible programming app. Students will also document completion of the programming task and evidence of learning how the rover can help scientists make discoveries. 

This activity was demonstrated during the Exploring Today's Classroom (ETC) Summit.

Computers draw lines and circles during many common tasks, such as using an image editor. But how does a computer know which pixels to darken to make a line?

Students will discover two common algorithms used to draw a line between two points and a circle of a given radius. 

Computers keep getting faster and faster, and by the start of the 1950s, they had gotten so fast that it often took longer to manually load programs via punch cards than to actually run them! The solution was the operating system (or OS), which is just a program with special privileges that allows it to run and manage other programs. So today, we’re going to trace the development of operating systems from the Multics and Atlas Supervisor to Unix and MS-DOS, and take a look at how these systems heavily influenced popular OSes like Linux, Windows, MacOS, and Android that we use today.

In this lesson, students are introduced to the need for encryption and simple techniques for breaking (or cracking) secret messages. Students try their own hand at cracking a message encoded with the classic Caesar cipher and also a Random Substitution Cipher. Students should become well-acquainted with the idea that in an age of powerful computational tools, techniques of encryption will need to be more sophisticated. The most important aspect of this lesson is to understand how and why encryption plays a role in all of our lives every day on the Internet, and that making good encryption is not trivial. Students will get their feet wet with understanding the considerations that must go into making strong encryption in the face of powerful computational tools that can be used to crack it. The need for secrecy when sending bits over the Internet is important for anyone using the Internet.

Students will be able to:
- explain why encryption is an important need for everyday life on the Internet.
- crack a message encrypted with a Caesar cipher using a Caesar Cipher Widget.
- crack a message encrypted with random substitution using Frequency Analysis.
- explain the weaknesses and security flaws of substitution ciphers.

Note: You will need to create a free account on code.org before you can view this resource.

The lesson elements in this module teach students about the privacy principle “Information about you on the Internet will be used by somebody in their interest — including against you”. They are designed to be independent and flexible, so you can incorporate them into any size lesson plan. Student resources are available at https://teachingprivacy.org/information-is-valuable/.

Summary of Learning Objectives: Students can give examples of how their data may be used to benefit others; students can investigate and evaluate how different online services use data, in order to make informed choices.

Target Age: High school, college undergraduate.

Learning Objectives:

1. Students can give examples of personal data that services or sites may share with other services or companies, and examples of how those “third parties” may use that data. Examples should include both information they explicitly post and supposedly hidden information.
2. Students can give examples of how having their personal data might benefit any of the following: friends/family, acquaintances, businesses, institutions, governments, and cybercriminals.
3. Students can explain the business model that allows companies that provide free or cheap online services to make money by selling consumer data to advertisers and/or data brokers.
4. Students can explain the difference between “opt-in” and “opt-out” models for information sharing, and relate those models to the lack of comprehensive laws regulating data sharing by companies, institutions, or governments.
5. Student can investigate how online services use data and who they share it with, and explain how they would use this information in choosing which services to use and which data to give those services access to.
6. Students can identify potential consequences of choosing particular privacy settings on apps, sites, and devices, in terms of how their data could be used by the parties who can see it — and whether those uses would likely be beneficial, neutral, or detrimental to themselves.

In this video excerpted from Pathways to Technology, you'll learn about the wide range of jobs that an information technology (IT) degree can make possible. From PCs to smartphones to cars, almost every tool we use today has computer technology embedded in it. The IT specialist is the person who keeps those computers operating and finds ways to make them run faster and more smoothly, so we can all get our work done. This video has discussion questions. 

In this kickoff to the Data Unit, students begin thinking about how data is collected and what can be learned from it. To begin the lesson, students will take a short online quiz that supposedly determines something interesting or funny about their personality. Afterwards, they will brainstorm other sources of data in the world around them, leading to a discussion of how that data is collected. This discussion motivates the introduction of the Class Data Tracker project that will run through the second half of this unit. Students will take the survey for the first time and be shown what the results will look like. To close the class, students will make predictions of what they will find when all the data has been collected in a couple of weeks.

Students will be able to:
- develop a hypothesis about student behavior over time, based on a small sample of data.
- describe sources of data appropriate for performing computations.

Note: You will need to create a free account on code.org before you can view this resource.

Staying safe online is a lot like staying safe in the real world. By helping a Digital Citizen sign up for a new app, students learn about the kinds of information they should keep to themselves when they use the internet -- just as they would with a stranger in person.

• Recognize the kind of information that is private.
• Understand that they should never give out private information online.

Users will need to create a free account to access this resource. 

This video explores our definition of coding and what it looks like to code with PBS KIDS ScratchJr. This video will explain coding to help get students ready for block-based coding. 

PBS KIDS Scratch Jr. app is now available for free from the App Store on iPad and from the Google Play store on Android tablets.

In this lesson, the class applies the problem-solving process to three different problems: a word search, a seating arrangement for a birthday party, and planning a trip. The problems grow increasingly complex and poorly defined to highlight how the problem-solving process is particularly helpful when tackling these types of problems.

Note: You will need to create a free account on code.org before you can view this resource.

This video shows an entertaining way to introduce Computer Science to students. It also offers an explanation of a public encryption key in a way that students can easily grasp. Students find out things they thought were safe on the internet are not safe.

Let's face it: Some online spaces can be full of negative, rude, or downright mean behavior. But what counts as cyberbullying? Help your students learn what is -- and what isn't -- and give them the tools they'll need to combat the problem.

Students will be able to:

• recognize similarities and differences between in-person bullying, cyberbullying, and being mean.

• empathize with the targets of cyberbullying.

• identify strategies for dealing with cyberbullying and ways they can be an upstander for those being bullied.

Users will need to create a free account to access this resource. 

Watch Ruff Ruffman show that while texting can be fun, creative, and a great way to stay in touch, it also has some drawbacks, in this animated video from RUFF RUFFMAN: HUMBLE MEDIA GENIUS. This video can be played to introduce a lesson on identifying, demonstrating, and applying personal safe use of digital devices.

Introduce students to nodes and graph theory and their use in operations research. Show how Dijkstra’s Algorithm can be used to find the shortest or quickest route between nodes in a network.

This lesson extends the drawing skills to include width and height and introduces the concept of random number generation. The class learns to draw with versions of the ellipse() and rect() that include width and height parameters and to use the background() block to fill the screen with color. At the end of the progression, the class is introduced to the randomNumber() block and uses the new blocks to draw a randomized rainbow snake.

Note: You will need to create a free account on code.org before you can view this resource.

This lesson combines all three types of binary representation systems (ASCII characters, binary number, and images) to allow for the encoding of more complex types of information in a record. After seeing a series of bits and being asked to decode them, the class is introduced to the idea that understanding binary information requires the understanding of both the system that is being used and the meaning of the information encoded.

Note: You will need to create a free account on code.org before you can view this resource.

Learn how text, images, and sound are converted into binary so they can be processed by a computer and how images and sound are compressed to create smaller files.

Includes information on ASCII, unicode, binary, pixels, bits, analog, digital, data compression, lossless compression.

Research shows that happiness in life is less about what you do and more about why you do it. When your actions have purpose they lead to positive results -- both for you and the world. Help students use the power of the internet to turn their personal passions into positive impact.

• Explain what it means to find your purpose and why it is beneficial.
• Consider different ways that people have used their digital footprint to make a positive impact on the world and whether you would do something similar.
• Reflect on what your own purpose might be, including a problem you want to solve and how you might go about solving it.

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