MUL Instruction :The MUL (unsigned multiply) instruction multiplies an 8-, 16-, or
32-bit operand by either AL, AX, or EAX. The instruction formats are:
MUL r/m8
MUL r/m16
MUL r/m3
The DIV (unsigned divide) instruction performs 8-bit,
16-bit, and 32-bit division on unsigned integers .A single operand is supplied (register or memory
operand), which is assumed to be the divisor . AH,DX,EDX.
mov edx,0 ; clear dividend, high
mov eax,8003h ; dividend, low
mov ecx,100h ; divisor
div ecx ; EAX = 00000080h, EDX = 3