Question

The hyphen in "two-thirds" is used because:

Answer 1

because "two-thirds" is a fraction, and when you are spelling out a fraction in words, there must be a hyphen to indicate that is is a fraction

Answer 2

Answer:

It is a fraction

Explanation:

When a fraction is written out in words, it is important to place a hyphen between the words in order to indicate the nature of the expression. This reduces confusion for the reader. However, this hyphen is only used when the number is present in the sentence in front of a noun, making it an adjective.