4. Buttons and Selection Code Ordering

4.1. Question 1

Rearrange the lines below to create a simple program that continuously checks if Button A is pressed.

If it is pressed, scroll the message “Yes”.

Drag and drop lines into the correct order and click to adjust indentation:

☰ while True:

☰ if button_a.is_pressed():

☰ display.scroll("Yes")

☰

☰ from microbit import *

4.2. Question 2

Put the code snippets in order to build a program that shows the letter “A” when Button A is pressed, or clears the display completely when nobody is touching the board.

Drag and drop lines into the correct order and click to adjust indentation:

☰ while True:

☰ from microbit import *

☰ display.clear()

☰ if button_a.is_pressed():

☰ else:

☰

☰ display.show("A")

4.3. Question 3

Arrange the lines of code to check for a single click event history on Button B.

When a click is detected, show a built-in happy face image.

Drag and drop lines into the correct order and click to adjust indentation:

☰ if button_b.was_pressed():

☰ display.show(Image.HAPPY)

☰

☰ from microbit import *

☰ while True:

4.4. Question 4

A student wants to set up a linked selection chain.
If Button A is down, show “A”. If Button B is down instead, show “B”. Otherwise, keep the screen clear.
Put the blocks in the correct vertical structure.

Drag and drop lines into the correct order and click to adjust indentation:

☰ display.show("A")

☰ from microbit import *

☰ display.clear()

☰ while True:

☰ else:

☰

☰ display.show("B")

☰ elif button_b.is_pressed():

☰ if button_a.is_pressed():

4.5. Question 5

Rearrange the segments to create a protected baseline counter.

When Button A is clicked, use the min function to increase the counter variable by 1 but cap it so it cannot exceed 9.

Drag and drop lines into the correct order and click to adjust indentation:

☰ display.show(guess_number)

☰ from microbit import *

☰ if button_a.was_pressed():

☰ guess_number = min(9, guess_number + 1)

☰ guess_number = 5

☰

☰ while True:

☰ sleep(200)