Hyphen in ages

[XselfesterX]

Do we say

1-Zach is 7-years-old

or

2- Zach is 7 years old

 

[Ruriha]

"Expressed as a number, age is always written in figures. If the age is used as an adjective or as a substitute for a noun, it should be hyphenated. Don't use apostrophes when describing an age range. A 21-year-old student."

 

[XselfesterX]

"Expressed as a number, age is always written in figures. If the age is used as an adjective or as a substitute for a noun, it should be hyphenated. Don't use apostrophes when describing an age range. A 21-year-old student."

Thanks!

Then I will use "I was a 7-year-old kid back then."