Does "five hundredth" mean 0.05 or 1/500?

I think what they are actually saying in sports is "he won by 5 hundredths of a second", meaning 5 one-hundredths of a second, not one five-hundredth of a second.

You have to listen carefully sometimes to hear the 's' at the end.

"Five hundredth of a second" should be plural, "Five hundredths of a second" (5/100 seconds or 0.05 seconds).

Ordinal numbers: 100th = one hundredth... 200th = two hundredth... 500th = five hundredth.

Fractions: 1/100 = one one-hundredth... 1/200 = one two-hundredth... 1/500 = one five-hundredth.

So 5/100 is "five one-hundredths."

But it can also be "five hundredths," because "a hundred" is often considered a synonym for "one hundred."

And if people don't pronounce the final "s" clearly, then "five hundredths" sounds like "five hundredth."

So there you go.