Benford’s Law: Why 1 Comes First

Benford’s Law is a curious mathematical rule that describes how often different digits (1–9) appear as the first digit in many real-life datasets. Surprisingly, lower digits (like 1) show up much more frequently than higher ones (like 9).

Simple Formula

The probability of a digit d being the first digit is:

📌 P(d) = log₁₀(1 + 1/d)

For example, the number 1 appears as the first digit about 30% of the time, while 9 appears only about 5% of the time! This pattern shows up in finance, science, populations, and even street addresses.

A fascinating rule of nature—numbers aren’t as random as they seem!

benford's law

Further reading.