Scratch Programming: Loops and Conditions

In Scratch, which block would you use to make a sprite do something only if a certain condition is true?

• Repeat block

• If block

• Forever block

• Wait block

Answer explanation

The 'If block' in Scratch allows a sprite to perform actions only when a specified condition is true, making it the correct choice for conditional execution. The other blocks serve different purposes.

What is the main purpose of an operator block in Scratch?

• To move the sprite

• To perform calculations or comparisons

• To change the sprite’s costume

• To play a sound

Answer explanation

The main purpose of an operator block in Scratch is to perform calculations or comparisons, allowing users to manipulate numbers and evaluate conditions, which is essential for creating interactive programs.

Which of the following is an example of a nested if condition in Scratch?

• Using two if blocks one after the other

• Placing an if block inside another if block

• Using an if block with a repeat block

• Using an if block with a forever block

Answer explanation

A nested if condition in Scratch occurs when one if block is placed inside another if block. This allows for more complex decision-making, as the inner if block can only execute if the outer condition is true.

What does the “repeat until” block do in Scratch?

• Repeats a set of instructions forever

• Repeats a set of instructions a fixed number of times

• Repeats a set of instructions until a condition is true

• Repeats a set of instructions until the sprite touches the edge

Answer explanation

The "repeat until" block in Scratch executes a set of instructions repeatedly until a specified condition becomes true, making it a useful tool for controlling the flow of a program based on dynamic conditions.

Which operator would you use in Scratch to check if two values are equal?

Answer explanation

In Scratch, the operator used to check if two values are equal is the single equals sign (=). This operator compares the values and returns true if they are the same, making it the correct choice for equality checks.

If you want a sprite to say “Hello!” only when the score is greater than 10, which block would you use?

Answer explanation

The correct choice is 'If score > 10' because it checks if the score exceeds 10. This condition ensures the sprite will only say 'Hello!' when the score is greater than 10, which is the desired behavior.

Which of the following is NOT a type of loop in Scratch?

• Forever

• Repeat

• Repeat until

• While

Answer explanation

In Scratch, the loop types include Forever, Repeat, and Repeat until. 'While' is not a recognized loop type in Scratch, making it the correct answer to the question.

What does the following Scratch code do? ``` repeat 5 move 10 steps end ```

• Moves the sprite 10 steps once

• Moves the sprite 5 steps

• Moves the sprite 50 steps

• Moves the sprite 15 steps

Answer explanation

The code repeats the action of moving 10 steps a total of 5 times. Therefore, the sprite moves 10 steps x 5 = 50 steps in total, making the correct answer 'Moves the sprite 50 steps'.

Which operator block would you use to check if a number is both greater than 5 and less than 10?

• Or

• And

• Not

• Join

Answer explanation

The 'And' operator checks if both conditions are true. To determine if a number is greater than 5 and less than 10, both conditions must be satisfied, making 'And' the correct choice.

How would you create a conditional block in Scratch that checks if a sprite is touching the edge?

• Use the “if on edge, bounce” block

• Use the “if touching edge” block inside an if statement

• Use the “repeat until touching edge” block

• Use the “wait until touching edge” block

Answer explanation

The correct choice is to use the 'if touching edge' block inside an if statement, as it allows you to create a conditional check specifically for when a sprite is touching the edge, enabling you to execute actions based on that condition.