REPEAT UNTIL a condition is true

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Quick Questions

Shade in the A or B circle for each question.

1. Which loop stops when the condition becomes TRUE?

A REPEAT 5 TIMES

B REPEAT ... UNTIL

2. You are filling a bucket and don't know how many scoops it will take. Which loop fits best?

A REPEAT add a scoop UNTIL bucket is full

B REPEAT 10 TIMES add a scoop

3. What is the stopping condition in this loop? REPEAT walk forward UNTIL you reach the wall

A walk forward

B you reach the wall

4. REPEAT knock on door UNTIL someone answers. When does the knocking stop?

A When someone answers

B After knocking 3 times

5. Which loop will never stop? Both start with the counter at 1 and the step is 'say hello'.

A REPEAT say hello UNTIL 1 is equal to 2

B REPEAT say hello UNTIL 1 is equal to 1

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1REPEAT Add 1 cup of water UNTIL bucket is full		AThe stopping condition is missing after UNTIL, so the computer doesn't know when to stop repeating.
2UNTIL password is correct		BREPEAT Eat one bite UNTIL plate is empty
3Use REPEAT UNTIL when you don't know in advance how many times the steps must run		CKeep adding water again and again until the bucket is full, even if we don't know how many cups it takes
4A loop must change something inside it so the stopping condition can become true		DREPEAT Roll the dice UNTIL the dice shows 6
5REPEAT Walk 1 step UNTIL I have wings		EThe stopping condition: the loop ends when this becomes true
6REPEAT Clap your hands UNTIL		FThe condition can never become true, because walking will never give you wings. The loop never stops.

Definitions

REPEAT ... UNTIL

Fill in the Blanks

Complete each line of code by filling in the missing parts.

______ Kick the ball UNTIL the goal is scored

REPEAT Stir the soup _____ the soup is hot

REPEAT Add 1 to steps UNTIL steps _ 10

REPEAT Add 1 to _____ UNTIL score = 10

REPEAT ___ 1 to count UNTIL count = 3

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A REPEAT

B ASK for the password

C READ the answer

D UNTIL answer is wrong

Question 2

A SET score TO 0

B REPEAT

C ADD 1 TO score

D UNTIL score < 0

Question 3

A REPEAT

B Throw the dice

C IF you roll a 6

Question 4

A UNTIL

B Stir the soup

C Taste the soup

D UNTIL it tastes good

Question 5

A SET energy TO -3

B REPEAT

C Run one lap

D SUBTRACT 1 FROM energy

E UNTIL energy = 0

Answer Key

REPEAT UNTIL a condition is true

Section A: Quick Questions

B — REPEAT ... UNTIL

A — REPEAT add a scoop UNTIL bucket is full

B — you reach the wall

A — When someone answers

A — REPEAT say hello UNTIL 1 is equal to 2

Section B: Match the Pairs

REPEAT Add 1 cup of water UNTIL bucket is full → Keep adding water again and again until the bucket is full, even if we don't know how many cups it takes

UNTIL password is correct → The stopping condition: the loop ends when this becomes true

Use REPEAT UNTIL when you don't know in advance how many times the steps must run → REPEAT Roll the dice UNTIL the dice shows 6

A loop must change something inside it so the stopping condition can become true → REPEAT Eat one bite UNTIL plate is empty

REPEAT Walk 1 step UNTIL I have wings → The condition can never become true, because walking will never give you wings. The loop never stops.

REPEAT Clap your hands UNTIL → The stopping condition is missing after UNTIL, so the computer doesn't know when to stop repeating.

Section C: Definitions

REPEAT ... UNTIL — A loop that keeps repeating its steps until a condition becomes true. Use it when you don't know how many times. Make sure the condition can happen, or the loop never stops.

Section D: Fill in the Blanks

REPEAT
  Kick the ball
UNTIL the goal is scored

REPEAT
  Stir the soup
UNTIL the soup is hot

REPEAT
  Add 1 to steps
UNTIL steps = 10

REPEAT
  Add 1 to score
UNTIL score = 10

REPEAT
  Add 1 to count
UNTIL count = 3

Section E: Spot the Error

D — The loop would stop on a wrong answer. It should keep asking until the answer is correct, so the line should be UNTIL answer is correct.

D — The score starts at 0 and goes up, so it can never be less than 0. The loop would never stop. It should be UNTIL score = 10.

C — A REPEAT loop must end with UNTIL and the stopping condition. IF belongs to branching. It should be UNTIL you roll a 6.

A — A REPEAT ... UNTIL loop must start with REPEAT. UNTIL goes at the end with the condition. Line 1 should be REPEAT.

A — Energy starts below 0 and keeps going down, so it never equals 0. The loop would never stop. It should start at a positive number such as SET energy TO 10.