Example 1
Byte does not know how far the star is. Which loop helps?
- The path is straight, but long.
- repeat until ⭐ with move forward inside.
- Byte moves until it lands on the star, then stops.
Answer: repeat until ⭐: move forward
🧩 Block coding, Grade 5 · session 3 of 14 · 60 minutes · 🎁 free with an account
Repeat until: loops that know when to stop
Sometimes you do not know how many times to repeat. Repeat until keeps going until something happens, like Byte reaching the star. The loop checks before each round.
A complete lesson · 60 minutes
Teach it, see it, practise it, all on this page.
Open this page with your learner and work down it, or press Teach this lesson to go through it one step at a time on a big screen. Every section has something to do.
- Warm-up4 min
- Repeat until7 min
- Patterns inside7 min
- Which loop?7 min
- code.org practical: puzzles 10–1318 min
- Activity 14 min
- Activity 24 min
- Activity 33 min
- Quiz5 min
- Set the project1 min
By the end you can
- Explain the difference between repeat n times and repeat until
- Use repeat until to reach a goal
- Predict how many moves a repeat until loop makes
Before you start
- Loops: repeat (session 2)
Have ready
- code.org open in another tab
- A ball or a soft toy
Grade 5 · ages 9 to 11 · beginner
Warm-up · think first
Keep clapping until I say stop!
Show the answer
You did not know how many claps; you kept going until something happened. That is repeat until.
Teacher tip: Play it twice with a different stopping point; ask how many claps they did.
Part 1 of 3 · learn, see, practise
Repeat until: stop when it happens
repeat until ⭐ runs the blocks inside again and again until Byte is on the star.
You do not need to count the squares: the loop stops by itself.
Real-life loops: keep walking until you reach the door; keep stirring until the sugar melts.
Practise it
Start with the warm-up and go as far as you can. The stretch questions are meant to be hard.
Warm-up
Warm-up
Core
Stretch 🔥
Answers (for the teacher)
- 6
- repeat until
- until they are clean
- 7
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Unlocking the rest of this lesson gives you:
- Part 2: Patterns inside repeat until, with practice at three levels
- Part 3: When to use which loop, with practice at three levels
- Class activity 1: Walk until
- Class activity 2: Repeat or until?
- Class activity 3: Count the moves
- A 8-question quiz
- After-class project: Until-stories
- Homework and a printable practice sheet with answers
- Teach mode and the minute-by-minute teacher's plan
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FAQ
Repeat until: loops that know when to stop: questions
What is a repeat until loop?
A loop that keeps running its blocks until something becomes true, such as reaching the goal; it does not need a number.
What is an infinite loop?
A loop whose stopping rule never comes true, so it never ends. Programmers avoid them.
Which code.org puzzles teach repeat until?
In the Classic Maze, repeat until appears around puzzle 10.
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