sleightless.

What three-digit number do people pick?

Nine hundred numbers to choose from, and the answers are nothing like evenly spread. Made-up numbers have a signature, and it is a signature accountants are trained to spot.

Answer it yourself first

Think of a three-digit number.

Anything from 100 to 999.

The answer usually given

What is usually said

There is no single expected answer here, which is what makes this question different from the others. What is expected is a shape: people avoid round numbers, avoid repeated digits, avoid anything ending in 0 or 5, and cluster in the middle hundreds.

The most useful published comparison is not a survey of people at all — it is what real numbers look like, below.

And what people are actually answering here

Out of 0 answers so far. Free to quote, with the sample size beside it so a reader can judge the weight.

Once this passes 1000 answers, the measurement replaces the claim above as the headline of this page, and the claim becomes the thing being checked rather than the thing being reported. Saying that in advance is the point: a threshold decided afterwards is not a threshold.

Real numbers start with 1. Invented ones do not

Take any large pile of naturally occurring figures — street addresses, river lengths, populations, invoice totals — and count how often the leading digit is a 1. The answer is not one time in nine. It is about 30%, with each higher digit less common than the last, down to about 4.6% for 9. This is Benford's law, and it turns up wherever numbers span several orders of magnitude.

People inventing a number do the opposite. A leading 1 feels small, unfinished, barely three digits at all. Asked to produce something that feels convincingly arbitrary, people reach for the middle: fours, fives, sixes, sevens.

Which is how fabricated data gets caught

Forensic accountants run Benford's law across expense claims, tax filings and election returns for exactly this reason. Genuine figures follow the curve. Invented ones are too flat and too fond of the middle, because they were produced by people trying to look random — the same instinct being measured on this page, applied to a spreadsheet instead of a stage.

So the count above is a small demonstration of a serious tool. If the answers here bulge in the middle hundreds and avoid the 100s, that is the fingerprint of human invention, and it is the fingerprint auditors look for.

What a performer does with it

Less than with the smaller ranges, and honestly so. Nine hundred options is too many to guess outright, so three-digit numbers are usually used differently: the performer predicts a property rather than the number — that the digits will not repeat, that it will not end in zero, that it will fall between 300 and 700. Those are much safer bets, and they feel like mind reading for the same reason the number itself never does.

How this is measured

Questions people ask

What three-digit number do people pick most?

There is no single dominant answer the way seven dominates one to ten, because nine hundred options is far too many. What is predictable is the shape: people avoid round numbers, avoid repeated digits, and cluster in the middle hundreds.

The running count above shows the distribution rather than a winner.

What is Benford's law?

That in naturally occurring numbers spanning several orders of magnitude, the leading digit is 1 about 30% of the time, and each higher digit is less common, down to about 4.6% for 9.

Numbers people invent break it, because a leading 1 feels too small to be a convincing choice.

How do accountants catch made-up numbers?

By checking whether the leading digits follow Benford's law. Genuine figures follow the curve closely; fabricated ones are flatter and favor the middle digits.

It is the same instinct this page measures, applied to a spreadsheet rather than a stage.

More

This is one of eleven questions in the full study, which asks for a card, a number, a vegetable, a fruit, an animal and more, and shows the running counts for all of them. The rest of the site is self-working card tricks you can play in the browser.