In this article's 2nd paragraph, headlined "How big are viruses?" are the following words:
"The virus particles are 100 times smaller than a single bacteria cell. The bacterial cell alone is more than 10 times smaller than a human cell and a human cell is 10 times smaller than the diameter of a single human hair."

May I point out that you really can't get smaller than one time the size of something at which point you disappear. What I assume is meant by the above paragraph is the following re-written set of words:
"The virus particles are 1/100 the size of a single bacteria cell. The bacterial cell alone is smaller than 1/10 the size of a human cell and a human cell is 1/10 the diameter of a single human hair."
Or
"The Virus particle's size is 1% of that of a single bacteria cell. That bacteria cell is less than 10% of the size of a human cell and that human cell's size is 10%  of the diameter of a human hair. So that makes the virus particle's size approximately 1/1000th the size of a human hair!" (Hope I got all the math right there! It's 1% of 10% of 10% of the diameter of a human hair)
Remember if I subtract one whole you (1 time smaller) there is nothing left. You want to speak about fractions, not whole numbers when speaking about something smaller. Unless of course it somehow is possible for the item being described to actually go into negative numbers. Physical items don't. You can only have one less of a physical item.

I know, I am feeling very much like a word Nazi, but I only do it for this particular peeve.....