pxt-calliope/olddocs/lessons/screen-wipe.md

# screen wipe blocks lesson

Clear the screen by pressing button "A".

## Topic

Clear Screen

## Quick Links

* [activity](/lessons/screen-wipe/activity)
* [quiz](/lessons/screen-wipe/quiz)
* [quiz answers](/lessons/screen-wipe/quiz-answers)
* [challenges](/lessons/screen-wipe/challenges)


## Prior learning/place of lesson in scheme of work

Learn how to **clear screen**, `clear screen` to turn off all the LED lights on the LED screen. We will be learning how to clear all LED lights on the LED screen using clear screen, input on button pressed as well as simple commands, such as show animation.


## Documentation

```cards
basic.clearScreen()
basic.showLeds(`
    . . . . .
    . . . . .
    . . # . .
    . . . . .
    . . . . .
    `)
input.onButtonPressed(Button.A, () => {})
```

## Objectives

* learn how to show a series of images on the LED screen
* learn how to run code when an input button is pressed
* learn how to turn off all the LED lights on the LED screen