Where in the sentence should the writer add a hyphen? I spend about-half my time, he spends two thirds of his time, and she spends a quarter, or maybe a third, of her time on research.
I spend about half my time, he spends two-thirds of his time, and she spends a quarter, or maybe a third, of her time on research.
I spend about half my time, he spends two thirds of his time, and she spends a quarter, or maybe a-third, of her time on research.
I spend about half my time, he spends two thirds of his time, and she spends a quarter, or maybe-a-third, of her time on research.