irule not working

Try this:

when HTTP_REQUEST {
    if { ( [string tolower [HTTP::host]] equals "www.mathzone.com" ) and ( [HTTP::uri] ne "/" ) } {
        HTTP::redirect "http://successinhighered.com/math/"
    }
}

If I understood you correctly, if the user adds ANY URI at all, you want to redirect them. So

http://www.mathzone.com does not redirect

http://www.mathzone.com/blah does redirect

Is that correct?