Taleb, the author of Black Swan, said: "Mathematics is not only a mathematical game, but also a way of thinking."
If the average depth of a river is 4 feet, never cross it.
1.22m is the average depth. Maybe this river is only 10 cm deep, and the middle of the river is two meters deep. This is the same as financial risk.
Hubbard, the founder of applied information economics, pointed out the key point of quantitative thinking in his book Digital Decision: "The concept of quantification is to reduce uncertainty, and it is not necessary to completely eliminate uncertainty."
Hubbard said: "The quantification method is hidden in the quantification goal." As long as you figure out what the real indicators are to be quantified, it is natural to quantify them.
The key to quantitative thinking is to realize what should be quantified. Even without accurate data, we can solve some seemingly unsolvable problems in life.
Interview questions in Silicon Valley include many such questions: How many gas stations are there in Seattle? How many Starbucks are there in Beijing?
This kind of problem is the famous Fermi problem, and the most classic one is: How many Piano tuner are there in Chicago?
Fermi estimation under quantitative thinking:
We will first make the following assumptions:
About 2.5 million people live in Chicago.
There are about two pianos for every 100 people.
This piano needs to be adjusted once a year.
It takes about 2 hours for each Andhadhun to tune a piano.
Each Andhadhun works 8 hours a day, including 2000 hours on the road in a year, so the total tuning time in a year is 1600 hours.
These figures are rough estimates and very inaccurate. Let's do a simple calculation with these figures. Every year, there are 50,000 pianos in Chicago that need tuning. After calculating the working hours in Andhadhun, it can be estimated that a * * * needs 63 Andhadhun.
In fact, there are about 83 Piano tuner in Chicago. It can be said that it is very close to the estimated value.
Those high-tech companies in Silicon Valley want to test whether you have any ideas and methods to solve problems without clues.
Quantitative thinking can make uncertain problems gradually clear. The focus is not on calculation, nor on the pursuit of accurate data, but on grasping the key points and selecting the indicators that need to be quantified.