# counter lesson Learn how to create a counter with with on button pressed. #show #number #screen #number #math #docs ### @video td/videos/counter-0 ## Topic Variables ## Quick Links * [activity](/microbit/lessons/counter/activity) * [challenges](/microbit/lessons/counter/challenges) * [quiz](/microbit/lessons/counter/quiz) * [quiz answers](/microbit/lessons/counter/quiz-answers) ## Prior learning/place of lesson in scheme of work Learn how to creating a **variable** to keep track of the current count. We will be learning how to create a counter app using a variable as well as simple commands, such as on button pressed, and show number. ## Documentation ```docs input.compassHeading() basic.forever(() => { }) let x = 0 if (true) { } basic.showString("Hello!") basic.showLeds(` . . . . . . . . . . . . # . . . . . . . . . . . . `) ``` * **variable**: [read more...](/microbit/reference/variables/var) * **arithmetic operators**: [read more...](/microbit/reference/types/number) * **on button pressed** : [read more...](/microbit/reference/input/on-button-pressed) * **show number** : [read more...](/microbit/reference/basic/show-number) ## Objectives * learn how to create a variable as a place where you can store data so that you can use it later in your code, accessible across all functions, and in nested code blocks * learn how arithmetic operators operate on numbers and return a number * learn how to run code when an input button is pressed * learn how to show a number on the LED screen, one digit at a time (scrolling from left to right)