I just noticed that it's not possible to type the ^ (power) symbol. For example if i wanted to type 2^3 i'd hit 2, twice ^ and 3. But no matter how often i hit ^ it won't show up. Copy-pasting it from another application works. I'm able to type the ^ symbol in any other application.
I'm using SpeedCrunch 0.12 (Qt 5.6.2) on 64 Bit Linux (KDE Neon)