Fancy Serial Numbers How To Determine And Added Value

Hi I'm new to this so if this doesn't make sense or is hard to understand I apologize I recently came acrossed a $5 Red Seal 1928 series B note it is circulated and everything I find says that it's not worth much money unless it has what is called a fancy serial number and from what I can see mine does how do I determine how much that serial number makes my bill worth or if it does it all the serial number is D78778652A can someone help I've looked all over for a place to be able to put in the serial number or what not also keeps showing me is that the low numbers and the high numbers are worth money doesn't say how much and it doesn't say who or where to ask these questions to