you should use Libreoffice in Linux.since there is no open office in Ubuntu repositories you should download it from official site. Download correct package from here http://www.openoffice.org/download/index.html
Extract the downloaded archive. Since it is an archive, you need to extract it. You can do that using your package program, or you can do it using this terminal command:
tar -xzvf Apache_OpenOffice_3.4.1_Linux_x86-64_install-deb_ar.tar.gz
You may need to change the name in the text above to fit your package.
type the following command into the terminal:
sudo dpkg -i *.deb
You will be required to provide an administrative password to run this command.
The executable file is located here: /opt/openoffice.org3/program/soffice
now create luancher for this excutable file from this site.