Remember: A program waits in memory until you press run. Then the processor reads one instruction, does it, and moves on, very fast but exactly as written.
Read and answer
Read the story, then answer.
The clothesline computerMina clicks the green flag, and her game springs to life. How did that happen? Mr. Reyes pegs cards on a clothesline, each with one instruction: set count to zero, repeat three times, add one, show count. The clothesline is the memory, holding the program before it runs. Teo wears a paper hat that says processor. He takes the first card and does exactly what it says, then the next, one at a time. At repeat, he jumps back to the start of the loop, round and round, and the count box goes up each time. When the repeats are used up, he moves on to the last card, and the screen shows three. Then Teo gets cheeky and skips a card, and the count comes out as two. A missing line makes a bug, so he puts it back.
1
The program is run, one card at a time. What does the cardboard screen show at the end?
430
2
Where does a program wait before you press run?
In the processorOn the screenIn memory
3
A processor reads all the cards at once.
TrueFalse
4
A computer never guesses. It does only what is written.
TrueFalse
5
A real processor does billions of tiny steps every .
yearweeksecond
6
Teo skips one add one card, and he does the other two. What does show count give?
132
Match, order and fix
7
Join each part to its job.
1memory
2processor
3repeat
4show count
Areads one instruction at a time
Bputs the count on the screen
Cjumps back to the start of the loop
Dholds the program before it runs
8
Put Teo's run in order.
The repeats are used up
Teo sets the count box to zero
Teo does add one, three times, round the loop
Teo reads show count and the screen shows three
9
Teo skipped a card, and the screen shows two. What is the mix-up to fix?
Put the missing card backMake the processor fasterPress run twice
10
A real processor takes a minute for four steps, like Teo.
TrueFalse
11
Mr. Reyes puts two add one cards inside the loop. What does the screen show?
12
Write four instructions for a grown-up to follow, one on each line.
13
Draw the clothesline with four instruction cards.
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