Why Japanese Numbers Need Special Attention
Japanese has two complete number systems: the native Japanese system (ひとつ, ふたつ, みっつ...) used for counting general objects 1 through 10, and the Sino-Japanese system (いち, に, さん...) borrowed from Chinese, used for everything else including large numbers, math, dates, and ages.
On top of this, Japanese uses counter words (助数詞 — josushi) — special suffixes attached to numbers that change depending on what you are counting. People use 人, flat objects use 枚, long objects use 本, small animals use 匹, and so on. There are over 500 counters, but about 20 cover daily life.
The JLPT N5 exam tests basic numbers, the native counting system, and approximately 10 common counters. Getting these right is essential because numbers appear in every section of the exam — listening (prices, times, dates), reading (schedules, quantities), and vocabulary (counter word selection).
The Sino-Japanese Number System (いち, に, さん...)
The Sino-Japanese numbers are the workhorse of the Japanese counting system. いち (1), に (2), さん (3), し/よん (4), ご (5), ろく (6), しち/なな (7), はち (8), きゅう/く (9), じゅう (10). These combine logically: 11 = じゅういち, 20 = にじゅう, 35 = さんじゅうご.
For larger numbers: 百 (ひゃく, 100), 千 (せん, 1,000), 万 (まん, 10,000). Note that Japanese groups numbers in units of 10,000 (万), not 1,000 like English. So 100,000 is 十万 (10 man) and 1,000,000 is 百万 (100 man). This grouping difference causes confusion for English speakers working with large numbers.
The numbers 4, 7, and 9 each have two readings. し/よん (4), しち/なな (7), く/きゅう (9). The alternate readings exist because し sounds like 死 (death), く sounds like 苦 (suffering), and しち is easily confused with いち (1). In most daily contexts, よん, なな, and きゅう are preferred.
| # | Kanji | Sino-Japanese | Romaji | Native (things) | Romaji |
|---|---|---|---|---|---|
| 0 | 零／〇 | ゼロ・れい | zero / rei | — | |
| 1 | 一 | いち | ichi | ひとつ | hitotsu |
| 2 | 二 | に | ni | ふたつ | futatsu |
| 3 | 三 | さん | san | みっつ | mittsu |
| 4 | 四 | よん・し | yon / shi | よっつ | yottsu |
| 5 | 五 | ご | go | いつつ | itsutsu |
| 6 | 六 | ろく | roku | むっつ | muttsu |
| 7 | 七 | なな・しち | nana / shichi | ななつ | nanatsu |
| 8 | 八 | はち | hachi | やっつ | yattsu |
| 9 | 九 | きゅう・く | kyuu / ku | ここのつ | kokonotsu |
| 10 | 十 | じゅう | juu | とお | too |
Red = two readings exist (4, 7, 9). Prefer よん・なな・きゅう in daily counting.
| # | Kanji | Reading | Romaji |
|---|---|---|---|
| 11 | 十一 | じゅういち | juu-ichi |
| 14 | 十四 | じゅうよん | juu-yon |
| 20 | 二十 | にじゅう | ni-juu |
| 35 | 三十五 | さんじゅうご | san-juu-go |
| 48 | 四十八 | よんじゅうはち | yon-juu-hachi |
| 70 | 七十 | ななじゅう | nana-juu |
| 99 | 九十九 | きゅうじゅうきゅう | kyuu-juu-kyuu |
| # | Kanji | Reading | Romaji |
|---|---|---|---|
| 100 | 百 | ひゃく | hyaku |
| 300 | 三百 | さんびゃく | san-byaku |
| 600 | 六百 | ろっぴゃく | rop-pyaku |
| 800 | 八百 | はっぴゃく | hap-pyaku |
| 1,000 | 千 | せん | sen |
| 3,000 | 三千 | さんぜん | san-zen |
| 8,000 | 八千 | はっせん | has-sen |
| 10,000 | 一万 | いちまん | ichi-man |
| 100,000 | 十万 | じゅうまん | juu-man |
| 1,000,000 | 百万 | ひゃくまん | hyaku-man |
- •Always use よん (4), なな (7), and きゅう (9) when counting unless a specific counter requires し, しち, or く.
- •Practice building numbers aloud: 256 = にひゃくごじゅうろく. Speed comes from drilling combinations.
- Sound changes: 300 = さんびゃく (not さんひゃく), 600 = ろっぴゃく, 800 = はっぴゃく. These are tested on JLPT.
- 10,000 grouping trap: when hearing prices in Japanese, mentally convert 万 units. 3万5千 = 35,000, not 35 million.
The Native Japanese System (ひとつ, ふたつ, みっつ...)
The native Japanese counting system only goes from 1 to 10: ひとつ (1), ふたつ (2), みっつ (3), よっつ (4), いつつ (5), むっつ (6), ななつ (7), やっつ (8), ここのつ (9), とお (10). Above 10, only the Sino-Japanese system is used.
This system is used when counting general objects without a specific counter — ordering food (ふたつください — 'two, please'), counting abstract things, or when you do not know the correct counter. It is the universal fallback that always works for quantities 1-10.
Children's ages 1-9 also use a variant of this system: ひとつ, ふたつ... are commonly used for young children's ages (3歳 can be said as みっつ in casual speech). For ages 10 and above, the Sino-Japanese system with 歳 (さい) is standard.
- •Memorize ひとつ through とお as a rhythmic chant — the pattern of つ endings makes them easier to remember as a set.
- •When ordering at a restaurant and you forget the counter, use this system: みっつください (three, please) always works.
- Common mistake: saying じゅういっつ for 11. The native system stops at 10. For 11+, use Sino-Japanese numbers with the appropriate counter.
- •The native numbers appear frequently in JLPT N5 listening — practice hearing the difference between ふたつ (2) and みっつ (3).
Essential Counter Words for JLPT N5
Counter words are attached after the number to specify what you are counting. The essential N5 counters: 人 (にん — people, but note: ひとり for 1 person, ふたり for 2), 個 (こ — small objects), 枚 (まい — flat things: paper, tickets, shirts), 本 (ほん — long things: pencils, bottles, roads), 匹 (ひき — small animals), 台 (だい — machines/vehicles), 冊 (さつ — books), 杯 (はい — cups/glasses).
Sound changes (連濁) make counters tricky. 本: いっぽん, にほん, さんぼん (not いちほん, にほん, さんほん). 匹: いっぴき, にひき, さんびき. 杯: いっぱい, にはい, さんばい. These irregular readings must be memorized — they follow patterns but the patterns have exceptions.
The most important counter for daily life is 個 (こ). It works for almost any small-to-medium object and is increasingly used as a general-purpose counter in casual speech, similar to how the native counting system (ひとつ, ふたつ) functions as a fallback.
| Counter | Counts | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 人nin | people | ひとり | ふたり | さんにん | よにん | ごにん | ろくにん | しちにん・ななにん | はちにん | きゅうにん | じゅうにん |
| 個ko | small objects | いっこ | にこ | さんこ | よんこ | ごこ | ろっこ | ななこ | はっこ | きゅうこ | じゅっこ |
| 枚mai | flat things (paper, tickets) | いちまい | にまい | さんまい | よんまい | ごまい | ろくまい | ななまい | はちまい | きゅうまい | じゅうまい |
| 本hon | long things (pens, bottles) | いっぽん | にほん | さんぼん | よんほん | ごほん | ろっぽん | ななほん | はっぽん | きゅうほん | じゅっぽん |
| 匹hiki | small animals | いっぴき | にひき | さんびき | よんひき | ごひき | ろっぴき | ななひき | はっぴき | きゅうひき | じゅっぴき |
| 杯hai | cups, glasses | いっぱい | にはい | さんばい | よんはい | ごはい | ろっぱい | ななはい | はっぱい | きゅうはい | じゅっぱい |
| 冊satsu | books | いっさつ | にさつ | さんさつ | よんさつ | ごさつ | ろくさつ | ななさつ | はっさつ | きゅうさつ | じゅっさつ |
| 台dai | machines, vehicles | いちだい | にだい | さんだい | よんだい | ごだい | ろくだい | ななだい | はちだい | きゅうだい | じゅうだい |
Red = irregular reading / sound change — these are exactly what JLPT tests. Deep dive: Complete Japanese Counters guide → · Sound Changes →
- •Memorize ひとり and ふたり first — these irregular people-counters appear in almost every JLPT listening section.
- •Learn counter sound changes in groups of 3: 1, 3, and 6/8 are where most changes happen (いっぽん, さんぼん, ろっぽん, はっぽん).
- にほん (2 long things) and にほん (Japan) are written and read the same. Context makes the meaning clear.
- 四人 is よにん (not しにん, which sounds like 死人 — dead person). Always use よ for 4 with 人.
Dates, Months & Days of the Week
Months are straightforward: number + 月 (がつ). January = 一月 (いちがつ), February = 二月 (にがつ), through December = 十二月 (じゅうにがつ). No exceptions, no irregular readings.
Days of the month, however, are highly irregular for the first 10 days and the 14th, 20th, and 24th. 1日 = ついたち, 2日 = ふつか, 3日 = みっか... These use the native Japanese number system with special readings. From 11日 onward, most follow the pattern: number + にち (じゅういちにち, etc.).
Days of the week follow a pattern based on celestial objects: 月曜日 (Monday/Moon), 火曜日 (Tuesday/Fire), 水曜日 (Wednesday/Water), 木曜日 (Thursday/Wood), 金曜日 (Friday/Gold), 土曜日 (Saturday/Earth), 日曜日 (Sunday/Sun). Knowing the kanji for each day helps you remember them as a system.
| Day | Reading | Romaji |
|---|---|---|
| 1日 | ついたち | tsuitachi |
| 2日 | ふつか | futsuka |
| 3日 | みっか | mikka |
| 4日 | よっか | yokka |
| 5日 | いつか | itsuka |
| 6日 | むいか | muika |
| 7日 | なのか | nanoka |
| 8日 | ようか | youka |
| 9日 | ここのか | kokonoka |
| 10日 | とおか | tooka |
| 11日 | じゅういちにち | juu-ichi-nichi |
| 14日 | じゅうよっか | juu-yokka |
| 20日 | はつか | hatsuka |
| 24日 | にじゅうよっか | ni-juu-yokka |
11日 shows the regular pattern (number + にち). Everything in red must be memorized — deeper dive: Reading Numbers & Dates →
- •Drill 1日 through 10日 as a set — these irregular day readings are a guaranteed JLPT N5 topic.
- •Days of the week trick: Mon-Sun = 月火水木金土日. The kanji appear in this order, and each maps to a natural element.
- 4月 = しがつ (not よんがつ), 7月 = しちがつ (not なながつ), 9月 = くがつ (not きゅうがつ). Months use the older readings for 4, 7, 9.
- 8日 = ようか (not はちにち). 20日 = はつか (not にじゅうにち). These exceptions are tested on JLPT every year.
Numbers in Real Life & JLPT
In daily Japanese life, numbers appear constantly: prices (さんびゃくえん — 300 yen), phone numbers (digit by digit), addresses (district numbers + building numbers), ages (number + 歳), and time expressions (number + 時/分). Being comfortable with number listening is essential.
The JLPT tests numbers primarily through listening. You will hear: store prices and making change, appointment times and scheduling, quantities being ordered, and phone numbers or addresses. The key skill is rapid recognition — you do not have time to mentally convert, so practice hearing numbers at natural speed.
A practical study method: practice with real Japanese prices. Look up restaurant menus, convenience store prices, or train fares online. Read the prices aloud in Japanese. This builds the number-reading automaticity that the JLPT requires.
- •Practice listening to prices at natural speed — Japanese cashiers speak quickly. Train with audio at 1.0x speed, not slowed down.
- •Phone numbers are read digit by digit: 090-1234-5678 = ゼロきゅうゼロ の いちにさんよん の ごろくななはち.
- Japanese uses 0 (ゼロ or れい). ゼロ is more common in daily speech; れい is used in formal contexts and weather reports.
- •For JLPT listening: when you hear a price, write the number immediately — do not wait to hear the whole sentence.
Teacher Notes by Language Background
Vietnamese also has counter words (classifiers) like con (animals), cai (general objects), and quyen (books), so the concept of Japanese counters will feel natural. The key difference is that Japanese counter sound changes (rendaku) are more complex. Vietnamese speakers often find the native Japanese number system (hitotsu, futatsu) unusual since Vietnamese does not have a parallel system.
Indonesian does not use counter words as extensively, so the Japanese counter system will be new. Start with ko (general objects) as your fallback counter — it works similarly to Indonesian buah. The 10,000-unit grouping may cause confusion since Indonesian uses the same 1,000 grouping as English. Practice converting between the two systems early.
Mongolian number structure is similar to Japanese in some ways (10+3 = 13), which helps with basic number building. However, Japanese counter words have no Mongolian equivalent. Focus on learning counters through daily use situations (ordering food, buying tickets) rather than memorizing lists. The irregular day-of-month readings (tsuitachi, futsuka, etc.) require dedicated drill time.
Frequently Asked Questions
How do you count from 1 to 10 in Japanese?+
How do you say 100, 1,000, and 10,000 in Japanese?+
What is the Japanese counter for people?+
Why does Japanese have two number systems?+
How many counter words do I need for JLPT N5?+
What happens if I use the wrong counter?+
Why do numbers 4, 7, and 9 have two readings?+
How do I learn the irregular day-of-month readings?+
Continue Learning
Master Numbers with Spaced Repetition
Nihongo Pass drills number recognition, counter words, and date readings using exam-adaptive SRS so they become automatic before test day.