The 1923 Reichsbank 20,000 Mark note in uncirculated condition is worth $2.
First of all, It's a 100 mark bill. And, It's worth about $2-$19
The 1923 German Mark 200,000,000, Note is very rare; High Grade Score, 90 in today U.S. Dollars can cost $250 and in good condition can be unlimited in the Auction or Collector's Market Value ! If one of 200,000,000 German Mark Note can be found. . . Living Life Enterprises Presents.
"Zwanzig Mark Alliierte Militarbehorde" is German for "20 Mark Allied Military Authorities." These notes were printed by the Allied Authority in Germany after the end of the Second World War, and the date on the note is likely 1944. These notes are not particularly rare, so it is likely worth less than $5US.
A perfect uncirculated note with a 7-digit serial number is worth $10. Ones with only 6-digits are worth $30. ($0.50 and $2 in Very Good, crisp used condition).
There are two versions of the 1980 10 DM note. The more common has "(c) Deutsche Bank 1963" on the back and is worth $12 in perfect uncirculated condition. The less common version does not have the copyright notice and is worth $25 (in UNC condition). Both notes still have a collectors value in Very Fine condition ($7 and $10 respectively) but any normal worn note is worth it's face value - they can still be exchanged for their Euro equivalent - see related link.
There are three versions of the 1910 issue German 20 Mark note. The more common have no watermark and are worth $80-$100 in uncirculated condition ($30-50 in Very Fine). The less common example with a watermark reading "20 Mark" is worth $350 in UNC and $150 in VF.
Most of the hyper-inflationary German 1923 notes are worth about $5 in Very Fine condition.
These bills date from the period of hyperinflation that followed WW1. Unfortunately most of the bills were worth about as much as tissue paper at the time, and many have not appreciated much since then. Yours might retail today for less than $1.
Since adopting the Euro in 2001, Deutsche Mark notes are no longer legal tender. They have a replacement value (in a German bank) of approx $7.50. A 1989-1999 uncirculated 10DM note is worth between $10-$20, depending on signature.
The word "book" traces its root to German, not Latin, but "note" comes from the Latin word nota, which means "to mark or note".
They are worth $5 in mint uncirculated condition, dropping to $1 in Very Good used quality.