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docs/reference/js/lessons/counter/challenges.md

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+# 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("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("A", () => {
+    count1 = count1 + 1
+    basic.showNumber(count1, 150)
+})
+input.onButtonPressed("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`.
+