Come on in - sit anywhere you like

• Find your nametag and stand it up on your desk
• Take a look at your grade in studentvue
• Discuss these questions with your neighbors:
  1. How many different numbers can we represent with 4 bits?
  2. How many decimal digits would we need to represent the same values?
  3. Can you come up with a new number system that expresses the same values using only one digit?

Terminal Activity

• Use Nano to make a file on your desktop
• Read the file in binary using xxd -b
• Read the file in hex

Last time we…

• Looked at parts of a computer
• Invented counting systems with everyday objects

Vocab review:

• Analog: Information in the real world
• Digital: Information converted for storage on a computer
• Abstraction: Taking something complex and making a simpler version
• Sampling: Collecting little pieces of information
• Loss: Information that you lose from sampling

One more - Who is this?

Fidelity

How closely does the digital information match the analog information?

• Low fideltiy (“lofi”) - the digital version does not match the analog version very well
• High fidelity (“hifi”) - the digital version does match the analog version well

Images: Levels of abstraction

1. Divide an image into pixels
2. Convert each pixel into a single color
3. Map each color to the closest available color
4. Convert the color to binary

Practice - Code.org Pixelation Tool

• Start with B&W

Each pixel is actually 3 lights

Practice - with colors

• Can you recreate this, using 3 bits per pixel?

This is a recap slide

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