Use the negative brightness button (f1) to reduce your screen light to 0

You should not be able to see

Now open atom (without looking!), write a function that takes one argument (an array) and returns the sum of each item in the array

Run it in Node (also without looking)

Check your results. Did it work? Try again!

http://adarkroom.doublespeakgames.com/

http://phildo.itch.io/monologue

http://flash.hoodamath.com/opendoors.swf

http://play.typeracer.com/

http://vim-adventures.com/