All (assuming the candidate really does have the experience :) ). However, the 3rd is a little strange unless you're targeting an audience that has a lot of non-native English speakers.

The Canadian Press Style Guide says:

<< In general, spell out whole numbers below 10 and use figures for 10 and above. >>

I always keep my Strunk & White Elements of Style nearby:

The 4th edition says:

Do not spell out numerals, unless they are being used in dialogue.

However, the 3rd edition rule used to require you to spell out numbers under 100, and use digits for numbers 100 and above.

This topic is progressing as I expected. No definitive answer on correct usage. :)

The Canadian Press Style Guide
In general, spell out whole numbers below 10 and use figures for 10 and above.

Strunk & White Elements of Style
The 4th edition says: Do not spell out numerals, unless they are being used in dialogue.

And then...

However, the 3rd edition rule used to require you to spell out numbers under 100, and use digits for numbers 100 and above.

Okay, the third edition rule must apply to my generation. What year was that fourth edition rule put in place? ;)

And then, is it 3rd or is it third?

The fourth edition is dated 2000. I too grew up with over/under 100 rule - I was going to quote that rule, but pulled out my S&W just to confirm and was surprised to the new dialogue rule.

personally i write digits eg. 21 when writing web content, spelling the number out seems verbose on a web page.

page1results - ooops, pageoneresults ;)

any way is correct.

There is no "proper" way; the editor dictates the style and usage. A "style guide" is merely that - a guide.

Having said that, it is generally accepted that numerals 1-10 are spelt out with numerals used thereafter. However, if you wanted to use numerals 1-10, then that is entirely your own choice and it certainly wouldn't be "wrong".

Syzygy

In general, spell out whole numbers below 10 and use figures for 10 and above.

This is what I was taught when I took some journalism classes in college in the mid 70's, specifically Copy Writing & Editing. Don't know if they still teach it that way.

Marshall