Words Related to Numbers in Japanese

◆How to count from 1 to 10

• 一（いち）”one”
• 二（に）”two” 
• 三（さん） “three”
• 四（よん／し） ”four”
• 五（ご） ”five”
• 六（ろく）”six”
• 七（なな／しち） “seven”
• 八（はち） ”eight”
• 九（きゅう） ”nine”
• 零（れい／ぜろ）”zero”

【About numbers with two readings】

• We basically use the following readings when referring to numbers in daily life: 4 (よん) / 7 (なな) / 0 (ぜろ). 
• When you count up from 1 to 10, you pronounce as:

「いち、に、さん、”し”、ご、ろく、”しち”、はち、きゅう、じゅう」.

• When you count down from 10 to 1:

「じゅう、きゅう、はち、”なな”、ろく、ご、”よん”、さん、に、いち」.

• When you say the time on the clock, refer to the post “How to Tell Time in Japanese”.
• When you tell your age, refer to the post “How to Say Your Age”.
• For decimals, use the reading: 4 (よん) / 7 (なな) / 0 (れい). 
• For other mathematics, such as calculations, we often use: 4 (よん) / 7 (なな) / 0 (ぜろ). 
• In addition to this, the number reads differently depending on the word or counter that follows it. (For counters, refer to the post “Japanese Counter – 1”.)

◆How to tell two-digit numbers

The reading of two-digit numbers is a combination of the tens and ones. (If the number in the ones’ section is 0, you only read tens, not ones.)

*

【Tens】

十（じゅう）”melodica”

二十（にじゅう）”recorder” 

三十（さんじゅう） “harmonica”

四十（よんじゅう） ”tambourine”

五十（ごじゅう） ”castanets”

六十（ろくじゅう）”handbell”

七十（ななじゅう）”melodica”

八十（はちじゅう）”recorder” 

九十（きゅうじゅう） “harmonica”

（百 [ひゃく]  ”tambourine”）

【Ones】

一（いち）”one”

二（に）”two” 

三（さん） “three”

四（よん／し） ”four”

五（ご） ”five”

六（ろく）”six”

七（なな／しち） “seven”

八（はち） ”eight”

九（きゅう） ”nine”

e.g.,

・25 is 20 (にじゅう) + 5 (ご). So you read it as 「にじゅうご」.

・20 has zero in the ones’ section, so you just need to read tens as にじゅう.

◆Decimals

• The numbers before (to the left of) the point are read as regular numbers, as explained in the previous post.
• The point is read as 「てん」.
• The numbers behind (to the right) the point are read one by one as “ones”.

e.g.,

12.34

12 (じゅうに)

. (てん)

3 (さん)

4 (よん)

→「じゅうに てん さん よん」

◆Fractions

Numbers are read in the following order: 

・the number written at the bottom (the denominator), 

↓

・the line「ぶんの」 (the vinculum), 

↓

・the number written at the top (the numerator).

e.g.,

⅔: さん (th denominator) ぶんの (the line) に (the numerator).