Quick Change

"Quick change" is a form of the Short Con in which the Hustler confuses a cashier into giving more change than they should. The most lucrative quick change technique is the "progressive", in which smaller denomination bills are thrust back at the cashier for consolidation into a higher denomination. "Here, give me a five for these ones." (then, while holding the five and the ones...) "Oh, wait. Go ahead and give me a 10. Let me see... one, two, three, four and five is .. yeah, a 10. Thanks."

If you were paying attention, that was five dollars becoming 10. A quick change artist can keep that rolling until he ends up walking away with a $100 bill.

An alternate technique is to pay for something cheap with a $100 bill, accept the change, and then offer to pay with a smaller bill. The object is to confuse the cashier into giving back the $100 bill without remembering to take back the change.

Yet another method is to show the cashier a large bill in your hand, but use sleight of hand to actually hand over a smaller bill. If the cashier doesn't look at it before putting it into the till, they'll give back more change than you deserve.

Naturally, the best way to avoid these schemes is by being cool, calm, nice and slow.

Not to be confused with the theatrical term for a very fast costume change. Not used in the film of the same name.

Examples of Quick Change include:

Comic Books

The Trickster does a variant near the start of The DCU's Crisis Crossover Underworld Unleashed, with rueful narration about how a charter member of The Flash's Rogues Gallery is now reduced to conning pizza boys.
José Carioca manages to get into the World Cup for free by responding to the cashier's request for money with a complaint that he hasn't gotten his change back yet. Joe takes the ticket and runs off while the cashier contemplates his statement.
An episode of the Finnish RPG-themed comic Peluri combined this with poking fun at D&D's complicated monetary system. After some back-and-forth involving copper, silver, gold, platinum and electrum pieces, the guard the conman was paying toll to ends up having to sell his weapon and armour to him.

Film

An old Abbott and Costello routine does a variation relying on Abbott's fast talk and Costello's stupidity. "Could you give me two 10s for a five?"
- As a variant, Abbott gets a few dollars off of Costello by counting 10 dollars in a non-standard fashion.

Abbott: All right, all right, I owe you $10, right?
Costello: Yeah, that's right.
Abbott: Right. 1, 2, 3. Say, how long were you in the Navy?
Costello: Six years.
Abbott: Six years! Well done you, six years. 7, 8, 9, 10.
[Costello tries it a moment later, but has trouble when the mark has been in the Navy 90 days.]

Demonstrated in great detail in the film Mercy Streets. Particularly strange because Mercy Streets basically exists to be mild Christian propaganda; one would think the filmmakers would have been a little more concerned about showing easily-imitable criminal acts.
The film The Grifters has an example of the third type of con. The protagonist holds up a $20 bill but actually pays with a $10 bill.
Juan does this trick at the beginning of Nine Queens. After succeeding, he tries again at the same shop with a different cashier, only minutes later. Naturally, he is recognized and exposed.
Done in Paper Moon.

Literature

In the novel American Gods, Mr. Wednesday casually pulls a variant of this, involving a credit card as well as cash, on a gas-station attendant. The exact details aren't mentioned, however: Neil Gaiman once stated in an interview that he'd deliberately tried to obfuscate the details of the cons used in the book, to prevent anybody from trying to replicate them in real life. (Didn't actually work, though. One of the bigger cons in the book was successfully replicated by a Canadian fan, who walked away with more than $6,000...)

Live-Action TV

Harry the Hat pulls this on Coach on Cheers, while talking to Cliff.
Done with a twist in CSI - Hypnosis is used, and the teller ends up making change for a $20 -- using $50s.
Done every which way in Hustle; whenever they pay for their drinks the barman is going to be left with less money than he started with. And he knows this, and still can't work out how it happens.
- The Real Hustle demonstrates how to make it work in real life, usually on store cashiers, and how not to fall for it.

Tabletop Games

The 2nd edition Dungeons & Dragons sourcebook The Complete Thief's Handbook. The end of Chapter 6 had a story that illustrated the second type of con, which they called the "short-change swindle".

Western Animation

In the South Park episode "Scott Tenorman Must Die", the titular Tenorman pulls this one on Cartman. Tenorman really pays for it later.
Hanna-Barbera's Hokey Wolf. The title character pulled this trick on a chuck wagon cook who has just baked some pies. After Hokey dresses up as an American Indian:

Hokey: Hows about us make 'um trade?
Cook: What kind of trade, Injun?
Hokey: Well, take your delicious home made pie for instance.
Cook: [snip] What about my delicious homemade pie?
Hokey: [Takes the pie] Wouldn't you say it's worth a can of your home made beans? [pulls a can of beans out of the cook's cupboard]
Cook: Sure it is!
Hokey: Fine, sir, fine! [Hands him the can of beans and grabs another can of beans out of the cupboard] Isn't two cans of beans worth a sack of your flour?
Cook: I guess so.
Hokey: [Hands him the 2nd can of beans and grabs a sack of flour out of the cupboard] Then I'll trade you this entire sack of flour for two measly pies.
Cook: You mean I gets my flour and my beans for only two of my measly delicious home made pies?
Hokey: Right sir, exactly. Ooh, you certainly drive a hard bargain sir!
Cook: [Laughs while running away] I sure got the best of that Injun! I have my beans and my flour back, and it only cost me [slams to a stop, outraged] TWO OF MY OWN PIES!

Real Life

Truth in Television, obviously. It will happen at least once to every person who works with both money and the public.
- A friend of Penn & Teller shows you how it's done.
- Banks have avoiding this trope as part of their teller training. If Teller tries this on a teller, all bets are off.
- The ten for a five variant was especially popular in Canada, due to how similar the pre-2019 iterations of the bills looked. (Nowadays, though, it's difficult, in that the images on the $5 are in landscape orientation while the images on the $10 have been in portrait orientation since early 2019. It may go back into vogue once the $5 gets portrait images, though.) Yes, all the bills are different colors, but blue and purple aren't that different.