When counting pencils

A unit called 'Jaru(자루)' is used.

"Jaru" is used after a word indicating quantity and is a unit of counting greasy writing tools, tools, and weapons, 

and it represents one pencil.

A bundle of pencils generally contains 12 pencils, which are called "1 Ta" or "1 Dâsu".

Ta (打): a word for counting twelve things as a unit

Dâsu (ダース): A unit of counting twelve things.

Das's etymology is the English word "dozen," 

and "dozen" is an English word that means a bundle of 12 words. 

Dusen was accepted as Dâsu in Japan, 

and this word came into Korea. 

It is said that the National Institute of Korean Language recommends that it be used after purifying it into a non-standard word rather than Dâsu. 

When counting pencils, use "Jaru(자루)" or "Ta(타)".