2.263 numbers followed by fractions

Besides their use as quantifiers linked by 'of' to a noun group, fractions can also be used after whole number or amount plus 'and', with a noun placed after the fraction. The noun must be plural even if the number is 'one'.

• You've got to sit there for one and a half hours.
• ...five and a quarter days.
• ...more than four and a half centuries ago

If you are using 'a' instead of 'one', the 'and' and the fraction come after the noun.

• ...a mile and a half below the surface.