Subtracting - (http://www.subtracting.org/) Any ideas what I could do with this domain?

I was thinking of setting up a website with information on subtracting - everything from the basic arithmetic to fractions and beyond. That way, I could benefit from a general keyword like 'subtracting' and long-tail keywords like 'subtracting fractions' & 'subtracting integers.' All of these have a pretty good search amount, based on the Google Keyword Tool.

I'm just not sure if there is anything else I can do to it or ways I could expand upon this idea. I'm also not sure what to use to create a site like this - standard wordpress, or would there be a suitable alternative CMS?

Any help is appreciated.