(I work at grocery store that happens to be running a sale on milk. I overhear another customer arguing with his spouse.)

Man: “Okay. We need a gallon of milk.”

(He reaches for the gallon jugs that are priced at $3.59.)

Woman: “Honey, the half gallons are on sale. They’re 10 for $10.00.”

Man: “That makes no sense.”

Woman: “Just grab two half gallons.”

Man: “But that’s more expensive.”

Woman: “No, they’re 10 for $10, while a gallon is $3.59. We don’t have to buy ten for the discount.”

Man: “That’s ridiculous.”

Me: “Look at it this way: You can buy a one gallon jug of milk for $3.59 or two half-gallon jugs for $2.00. It still equals one gallon.”

Man: *confused*

(The woman and I just exchange glances and shake our heads.)

Related:
Some Things Just Don’t Add Up, Part 4
Some Things Just Don’t Add Up, Part 3
Some Things Just Don’t Add Up, Part 2
Some Things Just Don’t Add Up