I think this shoul work

MOV A, #numberH
PUSH A
ANL A, #0FH
ADD A,#0
DA A < does not make any sense
MOV R3, A
POP A
ANL A, #0F0H
SWAP A
MOV B, #16H
XCH A, B
ADD A,#0
DA A < this also
XCH A, B
MUL AB
ADD A, R3
DA A



abhishek