Guess Your Number

Is your number on this card?

YES           NO

Is your number on this card?

YES           NO

Is your number on this card?

YES           NO

Is your number on this card?

YES           NO

Is your number on this card?

YES           NO

Explanation

How does this math number guessing trick work?

1

is the key number on this card

2

is the key number on this card

4

is the key number on this card

8

is the key number on this card

16

is the key number on this card

1 = 2⁰

2 = 2¹

4 = 2²

8 = 2³

16 = 2⁴

Add 1 if person says YES to the question, is your number on this card?

Add 2 if person says YES to the question, is your number on this card?

Add 4 if person says YES to the question, is your number on this card?

Add 8 if person says YES to the question, is your number on this card?

Add 16 if person says YES to the question, is your number on this card?

The person's number will be the sum of the key numbers the person said YES to.

These key numbers 1, 2, 4, 8, and 16 are based on the binary number system 2⁰, 2¹, 2², 2³, and 2⁴. 

Every number can be constructed as the sum of these key numbers.