I need to convert a decimal number to hex on a Motorola 12 series. I have 5 decimal digits in separate memory locations and will need to only go up to ffff

Any help would be appreciated!!

Jeff C
chem & phys teacher
Marietta, GA

Here's my approach, but there's got to be a more efficient way (or routines already written) out there.
1) Take every digit, multiply by the appropriate power of ten
2) Add all of the digits
3) Since this is stored as binary, take each nibble and compare to a lookup table

Any thoughts techie guys & gals?