Chrome OS

How do I take a screenshot on my Chrome OS device (e.g. Chromebook or Chromebox)?

hold down ctrl and press []]] = Your Chrome OS device captures the entire screen and saves it as a file into your Downloads folder.
or
hold down ctrl and press F5

How do I take a partial screenshot?

hold down ctrl and shift and press []]] = Use your mouse to draw a rectangle. Your Chrome OS device then saves it as a file into your Downloads folder.
or
hold down ctrl and shift and press F5

If it works, what does it look like?

Can you show me in a video?