How about the number reversal method. 16 is 61, 28 is 82, 40 is 04 (104). We already know 0 is 32, 10 is 50, and 25 is about 75. 33 is 3x3 is 9 so low 90s. Good enough for the passenger announcements.
Anyone know if the DEN airport got rid of that weird spare parts tax as part of this deal that has been discouraging airlines from having mx bases there?