There was a very rude old female cashier who was checking me out. I was trying to buy an item that was actually only 50% off (~$3) but was marked ~$1.50 or 75% off (original price was ~$6). The cashier scoffed at me & repeatedly (4 times) told told me "It would only be $1.50 if it was 90% off". All I did was ask her to remove it, which was literally a simple press of a button, so her comments were not only a reflection of her inability to do basic mental math, but was absolutely unnecessary to treat me like I'm an idiot.