Thread by @learn_adventure

Today I wanted to share the #한자

수(數)= number, several, count

수학(number+study)= mathematics
수학자(mathematics+person)= mathematician
숫자(number+character)= a number
소수(small+number)= decimal, fraction
지수(finger+number)= index number

수량(number+amount)= quantity
배수(multiple times+number)= multiple
산수(calculate+number)= arithmetic
대수(replace+number)= algebra
수열(number+to arrange in order)= progression

Additionally you can also use it as a prefix attached to a (round) number.

(Exemples will clarify)

수십 책= tens of books
수백 달러= hundreds of dollars
수천 명= thousands of people
수만 년= tens of thousands of years
수백만 원= millions of wons

Can also be uses as a prefix before 년, 월, 일,시간,세기, 개...to mean several (sth.)

수년= several years
수세기= several centuries

Lastly you can also use it as a prefix with 없이 and 많은. It takes the meaning of:

수없이= unnumerably
수많은= a lot of, lots of, many

그곳에는 수많은 사람들이 있었다.
There were a lot of people there.

나는 아직 할 일이 수없이 많다.
I still have a million of things to do.