The other day I came across this page and found a phrase strange to me.
a/one thousandth of a second = one one-thousandths of a second [= 1/1000 second]
The plural "s" confused me so much. Then, I checked the hundred entry of the same site.
one hundredth of a second = one one-hundredth of a second [= 1/100 second]
There is no plural "s" with "hundredth"! Now I'm relieved. The writer must have made a mistake. "One one-thousandth of a second" (without s) should be right.
But I checked a news site to make sure.
But Montgomery is the world record with a time of 9.78 seconds, one one-hundredths of a second faster than Greene's best time. (New York Post)
In one of the most thrilling 100-meter finals in Olympic history, Gatlin won gold by one one-hundredths of a second. (New York Post)
She finished fourth in the trials with a time of 11.11, just one one-hundredths of a second behind third-place finisher Lauryn Williams. (New York Post)
Now I'm totally confused again. Somebody help me (an English teacher from Tokyo). Both are OK? Why can you make it plural?