pxt-calliope/docs/reference/js/lessons/speed-button/quiz-answers.md

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2016-03-26 00:47:20 +01:00
# speed button quiz answers
counter that keeps track of how many times button "A" has been pressed #LED #screen #variables #docs #input
This is the answer key for the [speed button quiz](/microbit/lessons/speed-button/quiz).
## 1. What is a variable?
<br/>
A variable that is available throughout your main function.
## 2. If the rectangle below represents the BBC micro:bit, shade the area that shows the value of the variable count.
```
let count = 0
```
![](/static/mb/lessons/speed-button-0.png)
## 3. If the rectangle below represents the BBC micro:bit, shade the areas that will be displayed after two button presses on Button A. Explain why that particular area is shaded.
```
let count_ = 0
input.onButtonPressed("A", () => {
count_ = count_ + 1
basic.showNumber(count_, 100)
})
```
<br/>
![](/static/mb/lessons/speed-button-1.png)
After two button presses, **count** will be equal to 2.
## 5. If the rectangle below represents the BBC micro:bit, shade the areas that will be displayed after five button presses on Button A. Explain why that particular area is shaded.
```
count_ = 0
input.onButtonPressed("A", () => {
count_ = count_ + 1
basic.showNumber(count_, 100)
})
```
![](/static/mb/lessons/speed-button-2.png)
After five button presses, **count** will be equal to 5.