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Week 03 Β· The processor

Friday

Processor review
// One instruction at a time, billions of times a second
⏱ about 15 min

Friday: Processor review

Three neighbors are waiting at the Fix-It Bay door. One has a slow tablet and one has a stuttering game. One asks about blinking lights.

Rocket rubs his hands together. "Three cases, one morning!" Raven hands you the case log. "What do you notice first in each case?" she asks.

Nova hovers at your shoulder. "You know how the processor works now," she says. "Would you like a hint? Start every case with the word turns."

Week three review

  1. The processor follows instructions one at a time, very fast.
  2. With many apps open, it takes turns, so each app gets less time.
  3. A clock ticks billions of times a second to keep every step in time.
  4. Inside, everything is a switch, on or off, written as 1 and 0. One 1 or 0 is a bit.
  5. Each tick is fetch, do, next.

Case one: the slow tablet

A tablet with twenty apps open crawls. The processor is taking turns between twenty lists. Each list gets a tiny slice of time.

SOLVE CASE ONE
  • Read the question.
  • Tap your answer.
What is the kid-safe fix for the slow tablet?
Why does closing apps help?

Case two: the stuttering game

A game stutters on an older device. Each picture needs more steps than the processor can finish before the next tick deadline.

The game needs too many steps for the processor to finish in time. Which part of the processor sets that time?
WHY THIS EXERCISEThe clock sets the pace. If the steps for a picture take too many ticks, the picture is late.
StatementTrue or false?
A faster clock means more ticks each second.?
A game stutters when the processor finishes early.?
A simpler game needs fewer steps per picture.?
Closing other apps can help a stuttering game.?
WHY THIS EXERCISEStutter is a processor running out of ticks. Fewer steps or fewer lists both help.

Case three: the blinking lights

A neighbor saw four lights on a device blink in a pattern. The pattern was on, off, on, on. They ask if the lights could mean a number.

Lights on, off, on, on (values 8, 4, 2, 1). What number?
What do we call one single 1 or 0?
What is the name for counting with only 1 and 0?
TRACE IT: START WITH 3, DOUBLE IT, ADD 4, TAKE AWAY 2. PUT THE NUMBERS YOU PASS THROUGH IN ORDER
  • ?3
  • ?8
  • ?6
  • ?10
WHY THIS EXERCISEThe processor passes through 3, 6, 10 and 8. Order decides every answer.
PUT ONE TICK IN ORDER
  • Tap a card.
  • Then tap its spot.
1First
2Next
3Then
4Last
Try it
Pick one device at home. With a grown-up, count how many apps are open.
Close the ones nobody is using.
Notice whether the device feels quicker.
Safety first
Only close apps you opened yourself or that a grown-up says to close.
Never delete anything. Closing and deleting are different.

Three cases closed in one morning! Week three is done. Tomorrow the Crew Quest lets you become the processor.

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