Korea has two number systems. The Native Korean and the Sino-Korean. The Sino-Korean is derived from the Chinese numbers, while the native Korean is our pure Korean way of expressing numbers. I will show you both.

If you look carefully, the pattern is easier when trying to form bigger numbers. It's like math. 20 is considered two 10s so 이십. 50 is five 10s so 오십. 24 is just two 10s plus 4. 이+십+사=이십사. Hopefully the numbers are easy now.

Q: Which number system do I use?

A: Koreans use both in certain situations

Q: When do you use Native Korean?

A: You use native Korean for:

a. Counting physical objects followed by a unit. For example (5 books=다섯 권; 2 people=두 명) We'll learn certain counting units in a later chapter.

b. Age. For example (I am 22 years old. 스물두 살 입니다)

c. Hours of a clock. (1:00=한 시; 8:00=여덟 시)

d. Counting in general

e. Counting months*. (3 months later=삼달 후) (*Must use 달 when counting months with Native Korean)

Q: When do you use Sino-Korean?

A: You use Sino-Korean for:

a. Counting numbers higher than 100. Though there are words in native Korean for numbers higher than 100, it is not used as commonly. There's not even a word for 300. So if you have to say a number higher than 100, use Sino-Korean.

b. Counting for any unit of time except for hours. (For months in this case, you must use 개월 when counting months in Sino-Korean)

c. Months. The names of the months use Sino-Korean. (일 월=January; 칠 월=July)

d. Money/Currency

e. Math

f. Measurements (kilo, grams, liters, etc.)

g. Phone Numbers

h. Minutes. When telling time, you actually use both number systems. Native for the Hours and Sino for the Minutes. 4:38=네 시 삼십 팔 분)