Lesson Objectives
- Learn the 10 root digits of the Sino-Korean number system (일 이 삼 사 오 육 칠 팔 구 십)
- Understand how tens are built by simple multiplication (이십 = 20, 삼십 = 30…)
- Construct any number from 11 to 99 using just these 10 roots
- Know the key uses of Sino-Korean numbers: money, dates, phone numbers, minutes
- Read and say any number from 1 to 100 without hesitation
Two number systems — why two?
Korean has two entirely separate number systems: Sino-Korean (this lesson) and Native Korean (Lesson 16). Sino-Korean comes from Chinese and is used for money, dates, phone numbers, addresses, and minutes. Native Korean is used for counting objects, hours, and age. Today is the simpler system — just 10 roots and a pattern.
일 이 삼 사 오 육 칠 팔 구 십
These 10 words are everything. Every number from 1 to 99 is built from combinations of just these roots. Learn them cold — they are the foundation of the entire system.
👆 Tap any card to flip it and hear it spoken aloud
십 does all the work
To make a multiple of ten, you simply put the digit in front of 십 (ten). Twenty is literally "two-ten" (이십), thirty is "three-ten" (삼십), and so on. There are no irregular forms — the pattern holds perfectly up to 90.
👆 Tap each card to flip it — 🔊 to hear it
Tens + units. That's the whole formula.
To say any number between 11 and 99: say the tens, then say the units. 십일 (11) = ten-one. 이십오 (25) = two-ten-five. 구십구 (99) = nine-ten-nine. No exceptions, no irregular numbers.
십 alone = 10. 십일 = 11. 십이 = 12. Notice: for the teens (11–19) you say 십 + digit — not 일십 (that would mean 1×10, which doesn't exist). Only 20 and above use a leading digit: 이십, 삼십, etc. Ten itself is just 십.
Every number at once
The multiples of 10 are highlighted in blue. Tap any cell to reveal pronunciation — and hear it spoken aloud. Try reading each row before tapping.
👆 Tap any number to reveal and hear its pronunciation
When do you use Sino-Korean numbers?
Knowing which number system to use is as important as knowing the numbers. Sino-Korean (this lesson) covers money, dates, phone numbers, minutes, floors, and more.
| Use | Korean example | Notes |
|---|---|---|
| Money (원) | 오천 원 o-cheon won | 5,000 won. 천 = 1,000. 만 = 10,000 (new root — upcoming). Prices in Korea are always Sino-Korean. |
| Dates (월/일) | 삼월 십오일 sam-wol si-bo-il | March 15th. 월 = month · 일 = day. Both always use Sino-Korean numbers. |
| Phone numbers | 010-1234-5678 gong-il-gong… | Each digit read individually. 0 = 공 (gong) or 영 (yeong) in phone numbers. |
| Minutes (분) | 삼십 분 sam-sip bun | 30 minutes. Minutes always use Sino-Korean. Hours use Native Korean (Lesson 16). |
| Floors (층) | 오 층 o cheung | 5th floor. Building floors always Sino-Korean. |
| School years / grades | 이 학년 i hang-nyeon | 2nd year/grade. Academic years use Sino-Korean. |
Convert these to Korean — then tap to check
Each card shows a number in digits. Say the Korean aloud before tapping to reveal — and hear the correct pronunciation.
👆 Say it aloud — tap to check and hear it
Total items in your active deck
Numbers unlock money, dates, and schedules. Combined with your greetings and polite expressions, you now have real conversational range.
만 — The Number that Shapes Korean Prices
Korea uses 만 (man, 10,000) as its basic large-number unit — not 천 (1,000) like English speakers might expect. This means prices are always expressed in 만 and 천 combinations: 삼만 오천 원 = 35,000 won. When you hear a Korean price, your brain needs to shift to thinking in units of 10,000 rather than 1,000.
This trips up English speakers constantly — seeing "35,000" on a menu and mentally reading it as "thirty-five thousand dollars" rather than about $25 USD. The price of a decent restaurant meal in Seoul is around 만 원 to 이만 원 (10,000–20,000 won). A café coffee is about 오천 원 (5,000 won). Once your brain adapts to 만-based thinking, navigating Korean prices becomes second nature. 만 itself is introduced properly in Month 4 when shopping vocabulary arrives.
📚 Lesson 14 Homework
Before Lesson 15 — the Week 3 Review…
Write 일 이 삼 사 오 육 칠 팔 구 십 from memory 5 times each — no looking. Then write 백 (100). These 11 roots are all you need for the entire Sino-Korean system up to 999.
Say these numbers aloud as fast as you can, three times through: 11, 15, 23, 37, 42, 56, 68, 74, 89, 93, 100. Time yourself on the third pass — it should take under 20 seconds when fluent.
Practice reading prices: 오백 원 (500 won) · 천오백 원 (1,500 won) · 삼천 원 (3,000 won) · 오천 원 (5,000 won) · 만 원 (10,000 won). Note: 천 (1,000) was introduced in the usage table — use it as a preview for upcoming content.
Say today's date out loud in Korean. Format: [month]월 [day]일. For example, if today is March 15: 삼월 십오일 (sam-wol si-bo-il). Do this every morning as a habit — it locks in both number systems over time.
Lesson 15 is the Week 3 Review — it will test all of this week's vocabulary: greetings (L11), self-introduction (L12), polite expressions (L13), and Sino-Korean numbers (L14). Do a full deck pass tonight. 60 items — you should be clearing most of them quickly by now.