Repetition: loops in programs

Using loops to repeat instructions. Count-controlled loops save writing the same code many times

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Try each question. If you're stuck, leave it and come back. The answer key is on the last page.

1
What is a loop in a program? A) An instruction that repeats other instructions B) A way to turn a computer off C) A picture on a screen D) A type of mouse
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2
True or false? Using a loop saves writing the same instruction over and over. A) True B) False
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3
Which instruction would draw a square most efficiently in code? A) Repeat 4 times: move forward, turn right B) Move forward, turn right (just once) C) Move forward 100 times D) Turn right forever
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4
Complete the sentence. A loop in a program ___ instructions.
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5
If a loop runs 'Repeat 5 times: jump', how many jumps happen? A) 5 B) 1 C) 10 D) 0
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6
What is a 'count-controlled' loop? A) A loop that runs a set number of times B) A loop that never stops C) A loop that only runs once D) A loop that goes backwards
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7
True or false? In Scratch, the 'repeat 10' block is a kind of loop. A) True B) False
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8
Complete the sentence about loops in Scratch. In Scratch, the ___ block runs the instructions inside it again and again with no stop.
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9
A program needs to print 'Hello' 20 times. What is the best way? A) Use a loop that repeats 20 times B) Write 'print Hello' 20 times C) Write 'print Hello' once D) Print 'Hello' forever
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10
Match each loop type to what it does. Match each item on the left to one on the right. Left: Count-controlled loop, Forever loop, Repeat until loop Right: Runs a set number of times, Runs until the program stops, Runs until something is true
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Answer key

Repetition: loops in programs · for parents and teachers

1
An instruction that repeats other instructions
A loop tells the computer to repeat instructions, so you do not have to write them many times.
2
True
True. Loops are useful because they let you repeat instructions without typing them out many times.
3
Repeat 4 times: move forward, turn right
A square needs 4 moves and 4 turns, so 'repeat 4 times' is the most efficient way.
4
repeats
Loops repeat instructions. This is also called repetition.
5
5
The loop repeats 'jump' 5 times, so there are 5 jumps in total.
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A loop that runs a set number of times
A count-controlled loop repeats instructions a set number of times, such as 'Repeat 10 times'.
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True
True. The 'repeat 10' block in Scratch is a count-controlled loop.
8
forever
The 'forever' block in Scratch keeps running the instructions inside it until the program is stopped.
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Use a loop that repeats 20 times
A loop that repeats 20 times saves a lot of typing and makes the program shorter and easier to read.
10
Count-controlled loop → Runs a set number of times; Forever loop → Runs until the program stops; Repeat until loop → Runs until something is true
Different loops repeat in different ways. Some count, some run forever, and some stop when a condition is true.