Use hyphens in fractions whenever they are written as words, whether they function as a noun (two-thirds is more than one-half), adjective (a two-thirds majority) or adverb (two-thirds finished).

Do you write out two thirds?

Fractions as Words

For instance, we would write “2/3” as “two thirds”: He ate two thirds of the pizza by himself! This applies for most fractions. But there are two exceptions that have their own words: half (1/2) and quarter (1/4).

How is two thirds written?

For example, you can write two-thirds in fractional form – 2/3 – or as a decimal – 0.667 – and either way, you calculate two-thirds of a number by multiplying by that number.