I run Kubuntu 15.04 with the Kubuntu Team 5.3 Beta Backport ppa. I noticed that I can't use the numeric keypad with KCalc anymore. Anywhere else (Kontact, url bar chromium, libre office etc.) it works fine. I tried to press numlock but nothing.
However the number keys above the letters work fine.
*** This bug has been marked as a duplicate of bug 344638 ***