Sino Reference

일 (il) is not added to the 10s/100s/etc place.
 e.g. 111 is 백십일 not 일백일십일

There are two Sino-Korean words for 0. 영 is used for points, temperature, and math. 공 is used for telephone numbers.

In English, the grand unit changes in 1,000-fold intervals (thousand, million, billion, etc). In Korean, the grand unit changes in 10,000-fold intervals (만, 억, 조, etc). Commas are still inserted on a 1,000-fold interval, however when spelling out the number spaces are added on a 10,000-fold interval.