Every day, an elderly woman would travel from her village to a nearby town to trade. One day, a town shopkeeper asked her to sell him a pound of rich village butter. The old lady searched her village for the best butter she could find. On her next visit to town, she brought the butter to the shopkeeper and sold it to him.
After the women had left, the shopkeeper weighed the butter to see if he had received what he had paid for. The butter weighed less than a pound.
The enraged shopkeeper resolved to take the matter to court. The elderly lady was questioned about her actions. Perhaps the scale she used to measure was inaccurate.
The old lady claimed she didn't have a butter measuring device. "I don't have a measuring instrument," she explained. I've been buying a pound of bread from the shopkeeper on a regular basis. I weighed the loaf of bread and gave him the same amount of butter."
The shopkeeper was humiliated. His deception had come to light. The old lady was forgiven. Instead, the shopkeeper was charged with fraud.