# counter challenges Coding challenges for the counter tutorial. ## Before we get started Complete the following [guided tutorial](/microbit/lessons/counter/activity) At the end of the tutorial, your code should look like this: ``` let count = 0 input.onButtonPressed(Button.A, () => { count = count + 1 basic.showNumber(count, 150) }) ``` ### Challenge 1 ### @video td/videos/counter-1-2 Let's add the code to `count` when `B` is pressed. Add an event handler with `input->on button pressed(B)` then add the code to `count`. ``` let count1 = 0 input.onButtonPressed(Button.A, () => { count1 = count1 + 1 basic.showNumber(count1, 150) }) input.onButtonPressed(Button.B, () => { count1 = count1 - 1 // *** basic.showNumber(count1, 150) // *** }) // *** ``` ### Challenge 3 Now let's try to reset the counter when the BBC micro:bit is shaken. You will need to register an event handler with `input->on shake`.