Sino Numbers 1–10

The Sino-Japanese numerals are the backbone of counting in Japanese: every large number, most counters, all prices and phone numbers and times run on them (for why there is a second, native set, see Two Number Systems). Learning 一 through 十 is your first job — and it comes with one genuine complication that no amount of logic will smooth over: three of these ten numbers have two readings, and which one you use is not free choice. This page gives you the readings, explains the fork at 四, 七, and 九, and shows why that fork is the doorway to the whole reading-changes system.

The ten numerals

When you simply rattle off the numbers one to ten — counting steps, reps, items in the air — the usual chant is ichi, ni, san, shi, go, roku, shichi, hachi, kyū, jū. But the moment a number attaches to a word or a counter, the fork opens.

The fork: 四, 七, 九 and their double readings

四 can be shi or yon, 七 can be shichi or nana, 九 can be kyū or ku. Two forces drive the choice:

1. Homophone avoidance. し (four) is a homophone of 死 (shi, "death"), and しち (seven) is easy to mishear as いち (one). So yon and nana are widely preferred — clearer, and free of the death association.
2. Fixed convention. In many established words the "unlucky" or older reading is simply locked in, and you cannot swap it out.

The choice is fixed, not free

This is the part to internalize: each word or counter decides for you which reading of 四, 七, 九 it takes. The same digit surfaces differently depending on what follows it — and 四 even has a third face, yo, before certain counters.

Look at the times especially: 四時 = よじ, 七時 = しちじ, 九時 = くじ — three different readings (yo, shichi, ku) in a single counter. There is no shortcut; these are memorized. The point of meeting them now is to accept early that the reading rides on the following word, which is exactly the principle the reading-changes page develops in full.

Counting downward — where yon and nana take over

When Japanese speakers count down — a countdown, or ticking off items in reverse — they overwhelmingly switch to yon and nana on the way past: jū, kyū, hachi, nana, roku, go, yon, san, ni, ichi. Descending, しち and し are avoided because they are the readings most easily misheard, and the rhythm favors the clearer forms. It's a small habit, but it's a giveaway of whether the numbers sound native.

A cultural aside: why 四 and 九 make people uneasy

Because 四 sounds like 死 (death) and 九 sounds like 苦 (ku, "suffering, agony"), both numbers carry a faint unlucky charge — the Japanese cousin of Western unease about 13. Some hospitals and hotels skip room and floor numbers 4 and 9; hospital-room 四〇四号室 is a number you may never see. This superstition is also part of why the alternative reading よん feels safer to reach for.

Common mistakes

The through-line of every one of these: the reading of 四, 七, and 九 is decided by the word or counter attached to them, not by preference. Do not rigidly apply shi/shichi everywhere, and do not rigidly apply yon/nana everywhere either — learn each common word's fixed reading. That habit is precisely what the next page, on reading changes, turns into a system.

Key takeaways

• The Sino numerals are 一〜十: いち, に, さん, し/よん, ご, ろく, しち/なな, はち, きゅう/く, じゅう.
• 四, 七, 九 each have two readings — plus 四's special よ before some counters (四時 よじ).
• The choice is fixed by the following word, not free: 四月 しがつ but 四階 よんかい; 九月 くがつ but 九階 きゅうかい.
• よん and なな are the safe defaults for unknown counters and for counting down — but never override a word's fixed reading.