Money & maths
The numbers behind everyday decisions.
1:35Nobody can predict this ball
One ball through a board of pegs is pure chance, yet a thousand always pile into the same mountain. Here is why, and why casinos never worry.
1:40What is inflation?
Inflation is the average rise in prices, measured by repricing one basket of goods. At 3% a year, $100 of cash buys about $74 of today’s goods in ten years.
1:40Adam Smith's invisible hand, explained
Adam Smith's pin factory, computed: ten workers sharing 18 operations made 48,000 pins a day. Then the baker's self-interest and the invisible hand.
1:46How compound interest grows
At an example 7% a year, $1,000 becomes $7,612 in 30 years. $4,512 of it is interest earned on interest; simple interest stops at $3,100.