+129830 2*12^5 + 10*12^4 + 3 *12^3 + 1* 12^2 + 1*12 + 2 = 710366
11* 12^4 + 7 * 12^3 + 5 * 12^2 + 1 * 12 + 2 = 240926
710366 - 240926 = 469440
Convert back t base 12
469440 / 12 = 39120 R 0
39120 / 12 = 3260 R 0
3260 / 12 = 271 R 8
271 / 12 = 22 R 7
22 R 12 = 1 R 10
1 /12 = 0 R 1
1A780012
