How do I reinstall Numbers for El Capitan

I appeared to have a corrupt version of the Numbers app (had been 3.6.3) that was not importing correctly without gobbledygook. So it was suggested I trash it and reinstall from "Purchased" in the AppStore. However that does not work. It wants to install the latest version for 10.13 High Sierra and since that is incompatible I can not seem to get a download of what ever should be the correct version.