Depends on the date and condition. In general star notes carry a small premium if they're in decent condition. If the series itself is rare (and modern 50s are not) a star note can be worth a lot more than face value.
"Star" notes are issued to replace notes that were damaged during production. The following is from the Bureau of Engraving and Printing's website:
"When an imperfect note is detected during the manufacturing process after the serial number has been overprinted, it must be replaced with a new note. A "star" note is used to replace the imperfect note. Reusing that exact serial number to replace the imperfect note is costly and time consuming. The "star" note has its own special serial number followed by a star in place of a suffix letter. The serial number of the imperfect note that was removed is not used again in the same numbering sequence."
$10
$20
As you have seen in many other postings, a bill's serial number almost never has anything to do with its value.
Worth about 4 to 10 dollar depending on condition
A bill's serial number rarely affects its value or helps to ID it. Please post a new, separate question with the bill's date and what letter, if any, is next to the date.
Depends on year and how low the serial number is.
$10
$20
The percentage of a partial bill really has little to do with its value. Any bill is worth its face value if it contains a complete serial number and any part of the other serial number.
As you have seen in many other postings, a bill's serial number almost never has anything to do with its value.
$20
$5
The value is determined by the series (date) and condition.
The value is more dependent on the year (series) of the bill. The serial number by itself isn't enough information.
$20 Dollars.
100 dollars...idiot
Worth about 4 to 10 dollar depending on condition