Hundreds and thousands

In Korean a unit word counts as one of itself unless something says otherwise, so 백 is one hundred in the same way that 'dozen' is one dozen. A digit in front multiplies it: 이백 is two hundreds, 육백 six hundreds. Adding 일 tells the listener nothing new, so speech leaves it out. You may see 일백 written on a contract or a formal receipt, where every figure is spelled out in full so that nobody can alter it, but it is not said aloud.

The whole number is one word, so the rules of day 2 apply at every join. A final consonant before an empty ㅇ block links forward, as in 백이십 and 천오백. A k, t or p sound makes the next plain consonant tense, which is why 육백 is [육빽], just as 육십 was [육씹]. After ㄹ a following ㅂ stays plain, so 팔백 and 칠백 (chilbaek) come out as written. When a price is read at speed it is mostly joins, so it pays to know them.

Each slot is a digit followed by its unit word, and the slots are said biggest first, in the order the digits are written. An empty slot is skipped: 3,052 is 삼천오십이, with nothing said for the missing hundreds, and 3,002 is just 삼천이. There is no 'and' to add, unlike British English 'three thousand and fifty-two'. Written out in Hangul, anything up to 9,999 is a single word with no spaces, and that block of four digits is exactly what day 4 builds on.