a five-minute walk...or...a five minute walk Those two are correct. The others are wrong. It is bad style to use numerals in writing. Everybody will argue about the hyphen. I uphold that the hyphen is optional.

Phoenix, Here is the authoritative answer. :) Eliot is right. It is better to use 'five' than '5'. It's a five minute walk......okay It's a five-minute walk....okay a 5 minutes' walk...... "a" not used before plural a 5 minutes walk........"a" not used before plural It's five minutes' walk.....okay = walk of five minutes. This is definitely okay. ( It is similar to saying: It's my parent's house = the house of my parents.) You could also say: It's five minutes of walking. Brad is right if eliminating the hyphen causes confusion, but in this case the meaning is clear with or without the hypen, therefore it is not necessary. Although, if you use the form with the number (5-minute) then standard use requires the hyphen.

A five-minute walk. Here, "five minutes" is describing the walk; therefore it is an adjective, and because it is more than one word we call it a compound adjective. The hyphen makes it clear which words should stay together so we can see that they are the adjective. This is important, not optional. For example, if I say "She is a Japanese art student," does that mean she is an art student who is a Japanese woman, or a student who is learning about Japanese art? By using or not using the hyphens, this becomes completely clear (a Japanese-art student means she studies art from Japan; a Japanese art student means that she is a Japanese person).

5 minutes walk.

omg, I'm interested, too