Guess the numbers with your ears upright.

The number represented by the ear is the shape of 3. There is a digital nursery rhyme that says, 1 is as thin as a pencil, 2 is like a duckling in the upper reaches of the water, and 3 is like an ear that listens to sounds.

Ears are like the number 3, so March 3 is ear-loving day every year.