fraction has vs have

[Ma_linka]

Hi, why in the following sentence have instead of has was used? I thought fraction was singular and require the verb has.

A very small fraction of these reactions have been studied at the energies existing inside of the stars, and a large part of those few cases have been observed using LUNA.

Thank you!

 

[owlman5]

Hi, Ma linka. The writer was probably using "a small fraction" to mean "a small number of these reactions". With that thought in mind, it makes sense to use "have".

If I was talking about a fraction in arithmetic, I'd use the singular: 3/8 is greater than 1/16.

 

[Ma_linka]

Thanks, owlman 5, for explanation!