Para openSUSE Slowroll execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/X11:COSMIC:Apps/openSUSE_Slowroll/X11:COSMIC:Apps.repo
zypper refresh
zypper install cosmic-ext-calculator
Para openSUSE Factory execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/X11:COSMIC:Apps/openSUSE_Factory/X11:COSMIC:Apps.repo
zypper refresh
zypper install cosmic-ext-calculator
Para 16.0 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/X11:COSMIC:Apps/16.0/X11:COSMIC:Apps.repo
zypper refresh
zypper install cosmic-ext-calculator