In 1776 Adam Smith opened The Wealth of Nations with a pin. A worker on his own, he wrote, could perhaps make one pin in a day, and certainly not twenty. Split the job between people instead: one draws the wire, one straightens it, one cuts it, one sharpens it.

Smith gave three reasons it helps. Practice makes hands faster. Nobody loses time switching tasks. And people doing one thing invent tools: in his story, a boy paid to open and shut a steam engine's valve tied it to the machine with a string, and went off to play.

Smith wrote that he had seen a small workshop where just ten men made about twelve pounds of pins a day. At upwards of 4,000 pins a pound, that is about 48,000 pins, or 4,800 for each of the ten.

One honest footnote: his numbers came largely from the French Encyclopédie, and his own earlier lectures had said 2,000 each. Either way, splitting a job into steps multiplies what each person makes. It was Smith's first answer to where wealth comes from.

The pins and the workers' places are drawn as a sketch, not to scale.

How many did you guess, and which job would you split?

Sources: Adam Smith, An Inquiry into the Nature and Causes of the Wealth of Nations, 1776, Book I, chapter 1; Adam Smith, Lectures on Justice, Police, Revenue and Arms (student notes, ed. Edwin Cannan, 1896); Jean-Louis Peaucelle, "Pin making in the eighteenth century", 2009.
Sounds: our own, made in code (earshot, CC0).