Japanese Numbers 100–100,000 (Part 2)

Quick Recap

In Part 1, we learned that Japanese counting is beautifully logical. Number + じゅう + number gives you anything from 1 to 99. And 100 is 百 (hyaku).

Now we're scaling up. And while the logic stays the same, the sound changes get spicy.

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Hundreds: 百 (hyaku)

百 (hyaku) is the base unit for hundreds. The pattern is straightforward — number + 百 — but several numbers trigger pronunciation changes.

The Three Troublemakers

Most hundreds are just number + ひゃく. But three of them change:

• 300 → さんびゃく (sanbyaku) — ひゃく becomes びゃく
• 600 → ろっぴゃく (roppyaku) — ひゃく becomes っぴゃく
• 800 → はっぴゃく (happyaku) — ひゃく becomes っぴゃく

Why? The same phonetic reason as ふん/ぷん in minutes — certain sounds naturally "harden" or "double up" when they collide. さん softens the ひ to び. ろく and はち compress into っぴ.

Combining Hundreds with Tens and Ones

Just stack them, left to right:

• 350 = さんびゃくごじゅう (sanbyaku gojū) — 300 + 50
• 421 = よんひゃくにじゅういち (yonhyaku nijūichi) — 400 + 20 + 1
• 867 = はっぴゃくろくじゅうなな (happyaku rokujūnana) — 800 + 60 + 7
• 999 = きゅうひゃくきゅうじゅうきゅう (kyūhyaku kyūjūkyū) — 900 + 90 + 9

No new rules — just the hundreds sound changes plus everything from Part 1.

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Thousands: 千 (sen)

千 (sen) is the unit for thousands. Same pattern: number + 千.

Key Points

1,000 is just 千, not いち千. You don't say "one thousand" — just "thousand." Same as how you say 百, not いち百, for 100.

Two sound changes:

• 3,000 → さんぜん (sanzen) — せん becomes ぜん
• 8,000 → はっせん (hassen) — せん becomes っせん

The pattern by now should feel familiar. さん likes to voice the next sound (ぜん, びゃく). はち likes to double up (っせん, っぴゃく).

Combining Thousands

• 1,500 = せんごひゃく (sen gohyaku) — 1,000 + 500
• 2,800 = にせんはっぴゃく (nisen happyaku) — 2,000 + 800
• 3,650 = さんぜんろっぴゃくごじゅう (sanzen roppyaku gojū) — 3,000 + 600 + 50
• 9,999 = きゅうせんきゅうひゃくきゅうじゅうきゅう (kyūsen kyūhyaku kyūjūkyū)

You're now reading these left to right: thousands → hundreds → tens → ones. Same logic every time.

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Ten Thousands: 万 (man) — The Big One

Here's where Japanese and English part ways completely.

English groups numbers by thousands: thousand, million (1,000 thousands), billion (1,000 millions).

Japanese groups numbers by ten-thousands: 万 (man). There is no single word for "million" in Japanese — it's 百万 (hyakuman — "100 ten-thousands").

Good News: No Sound Changes

万 has zero irregular readings. Every number attaches cleanly. After the chaos of 百 and 千, this is a relief.

Note: 10,000 Is いち万, Not Just 万

Unlike 百 and 千 where you drop the いち, ten thousand is 一万 (ichiman). You always say the number in front of 万.

Combining Everything

This is where it all comes together. Read these right to left in "units":

• 15,000 = いちまんごせん (ichiman gosen) — 1万 + 5千
• 23,400 = にまんさんぜんよんひゃく (niman sanzen yonhyaku) — 2万 + 3千 + 4百
• 50,800 = ごまんはっぴゃく (goman happyaku) — 5万 + 8百
• 99,999 = きゅうまんきゅうせんきゅうひゃくきゅうじゅうきゅう (kyūman kyūsen kyūhyaku kyūjūkyū)

The formula: 万 + 千 + 百 + 十 + 一

Skip any unit that's zero. 50,800 has no thousands or tens, so you jump from 万 to 百.

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The Sound Change Cheat Sheet

Here's every irregular reading in one place:

百 (hyaku) — Hundreds

千 (sen) — Thousands

万 (man) — Ten Thousands

No changes. It's clean all the way through.

The Pattern

Notice the same culprits every time?

• さん (3) voices the next sound: ひ→び, せ→ぜ
• ろく (6) doubles up: ひゃく→っぴゃく
• はち (8) doubles up: ひゃく→っぴゃく, せん→っせん

Once you recognize these three troublemakers, you can predict the sound changes for any counter — not just numbers. This pattern appears with counters like 本, 杯, 匹, and more.

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Real-World Numbers

Let's practice with numbers you'd actually encounter in Japan:

Add 円 (en) at the end for yen. No sound changes with 円 — it just attaches cleanly.

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The Mental Shift: Thinking in 万

The hardest part for English speakers isn't the sound changes. It's rewiring your brain to think in units of 10,000.

When you see 50,000, your English brain says "fifty thousand." Your Japanese brain needs to say "five 万."

The trick: mentally move the comma. English puts commas every 3 digits (10,000). Japanese thinks in groups of 4 digits (1,0000). Once your brain makes this shift, large Japanese numbers become easy.

Practice

Try reading these aloud:

1. 250 → ？
2. 3,600 → ？
3. 8,300 → ？
4. 14,000 → ？
5. 72,500 → ？

Answers: にひゃくごじゅう、さんぜんろっぴゃく、はっせんさんびゃく、いちまんよんせん、ななまんにせんごひゃく

What's Next?

You can now handle any number from 1 to 100,000. That covers prices, addresses, phone numbers, ages, times, and most everyday situations in Japan.

Beyond 100,000, the same万 system just keeps stacking — but that's rarely needed in daily life. For now, drill the sound changes until 三百 automatically becomes さんびゃく and 八千 automatically becomes はっせん.

数字の冒険は続く！ (Sūji no bōken wa tsuzuku!) — The number adventure continues!