This DIV's height is 50% of the containing block. The containing block is 201px high. On a device with 1 pixel = 1px, how high is this DIV?

If you see a 1 pixel orange line, 100.5px was rounded down to 100px. If you see a vertical scrolling mechanism, it was rounded up to 101px. If you see no line, you may have a 200dpi screen, if you see a thicker orange line, something is wrong…