Credit to: u/Psychonian on reddit.

bind kp_end for 1

bind kp_downarrow for 2

bind kp_pgdn for 3

bind kp_leftarrow for 4

bind kp_5 for 5

bind kp_rightarrow for 6

bind kp_home for 7

bind kp_uparrow for 8

bind kp_pgup for 9

bind kp_ins for 0

bind kp_del for .

bind kp_enter for enter

bind kp_plus for +

bind kp_minus for -

bind kp_multiply for star

bind kp_slash for /

bind kp_numlock for numlock.