XFCE boots by default with the number lock off. For people who are used to other operating systems remembering their number lock settings from a previous session. this can be annoying. If you want your number lock to always default to “on” when you star a session, then follow these directions (taken from this source.)

Install the numlockx package in Synaptic Package Manager

  1. Open Synaptic Package Manager (Applications -> System -> Synaptic Package Manager)
  2. Search for “numlockx “
  3. If the package is not installed, then click the box next to it, mark it for installation, and then click Apply and close out of Synaptic once the installation is complete

Edit /etc/gdm/Init/Default

  1. Open a terminal (Applications -> Accessories -> Terminal)
  2. Type the following code at the prompt
    sudo nano /etc/gdm/Init/Default
  3. Enter the sudo password when prompted
  4. Once you are in the /etc/gdm/Init/Default file, scroll to the very bottom just before the exit 0 line
  5. Enter the following lines right before exit 0
    if [ -x /usr/bin/numlockx ]; then
    /usr/bin/numlockx on
  6. Hit Ctrl+o and then hit Enter to save
  7. Hit Ctrl+x to exit the file

When you reboot, the number lock should be on by default.