qalculate-kde is available as a KD antive option to qalculate-gtk. It is available at <http://prdownloads.sourceforge.net/qalculate/qalculate-kde-0.9.7.tar.gz?download>. Maybe the qalculate-gtk ebuild should be transformed in a qalculate ebuild with gtk and kde use flags.
(In reply to comment #0) Ok, maybe I'm typing faster than I should ;) Rewriting the previous comment to make it more legible: qalculate-kde is available as a KDE native option to qalculate-gtk. It is available at <http://prdownloads.sourceforge.net/qalculate/qalculate-kde-0.9.7.tar.gz?download>. Maybe the existing qalculate-gtk and this requested new ebuild should be substituted by a single new qalculate ebuild with gtk and kde use flags.
checking for kde-config... not found configure: error: The important program kde-config was not found! Please check whether you installed KDE correctly. It's for obsolete KDE 3.5.10, which is not supported by Gentoo.
btw, kde-misc/qalculate-applet is the closest thing KDE4 has for this