I ordered me a PocketCHIp to have a cheap, portable Linux computer with a physical keyboard with the added benefit if it running Debian out of the box. I quickly discovered that in Vim the dash or minus key is not what you'd expect. A quick search turned up that the key is mapped the numpad minus via xmopmap. To change the mapping to what is for me a better setting run sed -i 's/KP_Subtract/minus/g' ~/.Xmodmap and to apply the setting afterward run xmodmap ~/.Xmodmap.