failing to install LibreOffice

As in subject, am attempting to install latest LibreOffice on C7.

unpack all the rpm files, type "yum install *.rpm", or "yum localinstall *.rpm"
and yum spews the list of filenames (with the word "examining" in front
of each file) then says "nothing to do".

what the hey?

I tried "yum clean all" but it didn't help.

I also verified the sha256sum of the download.

Anyone got any good advice?

thanks in advance!