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docs/lessons/counter/activity.md

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+# counter activity
+
+Display a number with a variable. 
+
+### ~avatar avatar
+
+### @video td/videos/counter-0
+
+Welcome! This tutorial will teach you how to make a counter that increments when button A is pressed. Let's get started!
+
+### ~
+
+Let's start by creating a **local variable** `count` to keep track of the current count.
+
+```blocks
+let count = 0
+```
+
+The code under ``on button pressed("A")`` will run each time the user presses A. Let's add a line of code that increments `count` by `1`.
+
+```blocks
+let count = 0
+input.onButtonPressed(Button.A, () => {
+    count = count + 1
+})
+```
+
+Since the count has changed, it's time to refresh the screen display. Let's add a line of code to display the count on screen.
+
+
+```blocks
+let count = 0
+input.onButtonPressed(Button.A, () => {
+    count = count + 1
+    basic.showNumber(count)
+})
+```
+
+
+### ~avatar avatar
+
+Excellent, you're ready to continue with the [challenges](/microbit/lessons/counter/challenges)
+
+### ~
+

docs/lessons/counter/challenges.md

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