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AI Explorers 6-8 / Week 03 / Monday
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Week 03 · Encoding the World

Monday

Snapshots made of squares
// Pixels, color values and feature tables
⏱ about 20 min

Monday: Snapshots Made of Squares

Raven zooms in on a telescope snapshot on the big lab screen. Closer and closer she goes, until the comet disappears.

In its place is a grid of plain squares, each one a single flat shade.

"Where did the comet go?" Rocket asks. "It is just blocks now."

"It was always blocks," Raven says. "We were standing too far back to notice."

Nova floats up to the screen and taps one square with a beam of light. "Each of these has a name," she says. "And each one is stored as numbers."

Rocket squints at the grid. "So Sky Sorter never sees a comet. It sees a pile of numbers."

Pixels

A digital picture is made of a large number of small spots of color. These spots are called pixels.

Pixel is short for picture element. Each pixel shows one color.

From far away, your eyes blend the pixels into smooth shapes. Up close, you can see the grid.

Every telescope snapshot Sky Sorter receives is a grid of pixels.

CHECK YOUR PIXEL KNOWLEDGE
  • Read the question.
  • Tap your answer.
What is a pixel?
Pixel is short for which two words?
Why did the comet seem to vanish when Raven zoomed in?
StatementTrue or false?
A digital picture is made of many small spots of color.?
Each pixel shows one color.?
A telescope snapshot is one giant pixel.?
Sky Sorter works with numbers, not with the sky itself.?
WHY THIS EXERCISEKnowing a picture is a grid of numbers is the key to how a computer can sort it.

Encoding

To store a picture, a computer needs an encoding. An encoding is a planned way to turn information into numbers or symbols.

Encodings are everywhere. A map key turns symbols into places. A score sheet turns a game into numbers.

This week, you will try more than one encoding for the same snapshot and compare them.

WHICH IS AN ENCODING?
  • Read the question.
  • Tap your answer.
A map key where a blue line stands for a river. Is that an encoding?
A score sheet where each goal is written as a tally mark. Is that an encoding?
A random scribble with no rule behind it. Is that an encoding?
ZOOMING IN ON A SNAPSHOT
  • ?You see a smooth comet with a long tail.
  • ?The edges of the tail start to look jagged.
  • ?You can make out separate squares.
  • ?One square fills the screen with a single flat shade.
WHY THIS EXERCISEZooming in shows that a smooth picture is really a grid of separate pixels.
One small spot of color in a digital picture is a ____.
A planned way to turn information into numbers is an ____.
A grid is 5 squares wide and 5 squares tall. How many pixels is that? Type a number.
WHY THIS EXERCISEThe number of pixels sets how much detail a picture can hold.
Try it
Look very closely at a printed photo in a newspaper or magazine, or at a cross-stitch or tiled floor.
Can you find the small spots or squares that make up the bigger picture?
For a grown-up
This week, your student encodes pictures as numbers using graph paper and pencils.
No lesson connects your student to a real AI tool, chatbot or app.

Good start. Tomorrow you will turn colors into numbers.