In saucy the combination is Alt + LShift + NumLock. The problem is that it is not listed in Settings > Keyboard > Shortcuts > Universal Access.
It's also difficult to find Settings > Universal Access > Pointing and Clicking > Mouse Keys (Control the pointer using the keypad) to go back to normal behavior after using the combination by mistake.
In fact it was easier for me to find org/gnome/desktop/a11y/keyboard/mousekeys-enable=true using dconf dump / (this is a paradox about accessibility! )
In saucy the combination is Alt + LShift + NumLock. The problem is that it is not listed in Settings > Keyboard > Shortcuts > Universal Access. desktop/ a11y/keyboard/ mousekeys- enable= true using dconf dump / (this is a paradox about accessibility! )
It's also difficult to find Settings > Universal Access > Pointing and Clicking > Mouse Keys (Control the pointer using the keypad) to go back to normal behavior after using the combination by mistake.
In fact it was easier for me to find org/gnome/