Data on the Internet

Data is stored and transmitted online efficiently using many different kinds of hardware and software to send it quickly and accurately. Data can be compressed to take up less storage room and transmission time and, at the core, the entire system is made up of simple circuits that work with binary information that flows at an incredible speed all around the world.

This flexible lesson offers the teacher the opportunity to reteach key concepts such as binary, abstraction, Internet functionality and also teachers the layers of hardware abstraction from transistors and logic gates up to computing devices.

Journal (5 min)

Review Presentation on Binary and the Internet (20 min) optional

Activity 1: Data compression (10 min)

Activity 2: Presentation on Logic gates and hardware abstractions (20 min)

Wrap Up (5 min)

Assessment can be in class or can be used as homework. (20 min) optional

• MP2: Reason abstractly and quantitatively.
• MP6: Attend to precision.
• MP7: Look for and make use of structure.

• N-Q.1-3: Reason quantitatively and use units to solve problems
• A-CED.1-4: Create equations that describe numbers or relationships

• RST 12.3 - Precisely follow a complex multistep procedure

• 4. Analyzing and interpreting data
• 5. Using mathematics and computational thinking

• HS-ETS1-2. Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering.

The Computer Science Field Guide http://csfieldguide.org.nz 

Coding and compression: http://csfieldguide.org.nz/en/chapters/coding-compression.html

Data representation: http://csfieldguide.org.nz/en/chapters/data-representation.html 

Use the binary number calculator to check conversion calculations

How computer memory works (5:05) http://ed.ted.com/lessons/how-computer-memory-works-kanawat-senanan

Presentations: Unit3Lesson14_InternetData_Presentation, Unit3Lesson14LogicGates_Presentation.

Worksheets: Accompanying student notes to be filled in. Unit3Lesson14_InternetData_StudentHandout, Unit3Lesson14LogicGates_Handout. Also Unit3Lesson14_InternetData_ReviewSection

 Journal (5 min)

How does information get from one computing device to another using the Internet? (also on Slide 1 of the Unit3 Lesson14_InternetData_Presentation)

Slides 2-3 review the basic steps to sending information online: 

• Information is encoded in binary, then, (check to see if students remember how to do decimal to binary conversions)
• divided up into packets and sent
• decoded into words, pictures, etc when it arrives.

This is a review of unit 3. Pair, share and discuss. Identify weak areas of student understanding.

Review Presentation on Binary and the Internet ( 20 min)  - optional

If students need additional review: provide the handout: Unit3Lesson14_InternetData_ReviewSection (to accompany slides 4-9) and continue with the presentation, otherwise use the handout as an assessment.

• SLIDE 4: Fill in the blanks using words on the handout to describe the important features of internet communication.
• SLIDE 5: define protocol and ISP
• SLIDE 6: each device has an IP address that is looked up using the DNS
• SLIDE 7: packets are routed, paths are redundant
• SLIDE 8: review binary codes and number conversion
• SLIDE 9: answers to binary questions from SLIDE 8

Activity 1: Data compression (10 min)

Distribute Unit3Lesson14internetData_StudentHandout (slides 10-11) on data compression and abstractions from low level to high level with notes to accompany the video how computer memory works (5:05)

• SLIDE 10: compression saves time and storage. Look up lossy and lossless compressions (Lossless compression reduces the number of bits used and trasmitted, which can be reconstructed to the original data without any approximation; Lossy compression significantly reduces the number of bits at the cost of accurately reconstructing the original data)
• SLIDE 11: abstractions from low level to high level
• SLIDE 12: different file formats have characteristics for their intended uses and different media have advantages and disadvantages for their intended use (cost, stability, peformance, size, etc)

Activity 2: Presentation on Logic gates and hardware abstractions (20 min)

Present Unit3Lesson14_LogicGates_Presentation about hardware abstraction.pptx

Distribute Student handout: Unit3Lesson14LogicGatesHandout.docx

1. Prompt: Ask what really goes on inside of computers.
2. Computers are fast and accurate. To show how quickly they can do caclulations, demonstrate google search engine’s ability to instantly provide the answer to complicated calculations like 271839 to the 23^rd power
3. All data is in binary so all calculations must be in binary
4. Inside each chip are circuits.
5. If you could see inside a chip you’d see the communication lines for the bits, like roadways, and the processing units like buildings
6. Abstractions: the CPU is made of circuits, circuits are made of logic gates.
7. Follow bits through a calculation. The number 7 is pressed on the keyboard sending 00000111 to the CPU to be processed
8. The algorithm for addition is invoked when the “+” sign is pressed and will start up when the 2^nd number is entered.
9. 21 is pressed followed by = and the addition algorithm starts with the rightmost bits and adds up each column
10. addition is done with logic circuits. Logic circuits are made up of logic gates. There are picture symbols for each gate
11. looking at the AND gate, how many different input values can A have? How many different output values can Q have?
12. Use a truth table to show the inputs and outputs of a logic gate
13. The not gate, or inverter, changes a signal to its opposite
14. There are logic gates in an addition circuit
15. How logic gates add 2 digits
16. How logic gates add 3 digits
17. How the OR gate works
18. The deeper you look into what is happening the better you can understand what is really going on inside of a computing device.
19. Diagram of layers of abstraction from transistors up to computing devices.
20. Sample lotic questions
21. Sample AP ® type question
22. Career connections in circuit design

 Wrap Up (5 min)

Assessment (20 min) optional or can be used as homework.

 Also available Logic Gates additional practice handout and informational article.

More than any other lesson so far, this lesson should be customized to meet the needs of the students. If they have a background in electronics and logic circuits from science or STEM classes, or have a firm grasp of binary number conversion and how the internet works, these sections of the lesson can serve as a very quick review skipping past the slides with extra detail.

For advanced students: Use the Unit3Lesson14 assessment and the Unit 3 Lesson 14 Data on the Internet - Review Section as summative assessments after a brief review.

For students who do not have this background knowledge, use the presentations and notes.

Notes and exercises for binary encoding, data compression, logic circuits, how the internet works and layers of hardware abstraction.

Unit 3 Lesson 14 Summative Assessment

and 

Unit 3 Lesson 14 Data on the Internet - Review Section

can be used as a formative or summative assessment.