not 1. Fractional amounts such as .7, 1.6, .2 are also plural in form. Even 0 is plural. (there are 0 words in this sentence with more than 12 characters)
there are 0 cats in the room. there are 3 cats in the room. The phrase "there is 1 cat in the room" is an example of plural's counterpart, singular.
Two halves are better than one, even though two halves is equal to one. While one half is singular, two halves is plural.
And we wouldn't say "two halves are plural".
Yet, two halves are one, is fine.