probably should be in homework help.
There are a lot of ways to do it, the specific plc you write it for will matter heavily on how its done. In my experience with allen bradley ones I'm leaning toward a timer or counter and use the bit field distribute (BTD) block to map out a byte to the indicated outputs.
You could go down the state machine route and use a sequencer for it. Lot of good options. More specific information would be helpful.

 

One issue with writing example PLC programs is the wide differences with the commands available in any particular make.
For example, my preference lies with Mitsubishi PLC.
These have instructions that offer commands that are aimed at different number bases, BCD, DEC, etc.