Translation guide
The English verb 'multiply' covers several distinct meanings: mathematical multiplication, increasing in number or amount, and biological reproduction. This guide helps learners choose the right Japanese expression for each context.
Performing the arithmetic operation of multiplication, or stating that one number is multiplied by another.
The standard verb for multiplication. Used in the pattern AにBを掛ける (multiply A by B). In casual math speech, A掛けるB is common.
3に4を掛けると12になります。
If you multiply 3 by 4, you get 12.
この式では、xにyを掛けてください。
In this formula, multiply x by y.
A more formal or technical term for multiplication, often used in written mathematics or formal contexts.
この値を係数に乗じます。
Multiply this value by the coefficient.
A technical noun-verb compound meaning 'to perform multiplication'. Used mainly in computing or formal math contexts.
このプログラムは二つの行列を乗算します。
This program multiplies two matrices.
To cause something to become much larger in quantity, or to increase rapidly.
The most common and versatile verb for increasing a number or amount. Works for both concrete and abstract things.
新しい投資で利益を増やしたい。
We want to multiply our profits with new investments.
運動して筋肉を増やした。
I multiplied my muscle mass by exercising.
Intransitive counterpart of 増やす. Means 'to increase' or 'to multiply' on its own. Use when the subject itself increases.
Means 'to double' or 'to multiply several times'. Emphasizes a dramatic increase, often in business or statistics.
売上が昨年比で倍増した。
Sales multiplied compared to last year.
Specifically for increasing assets, wealth, or living things like plants or animals. Has a nuance of propagation or breeding.
To cause living organisms to produce offspring or to propagate.
The standard term for breeding or propagating animals or plants. Transitive: to make something multiply.
この農家は牛を繁殖させている。
This farmer multiplies his cattle.
Intransitive: to multiply or breed on their own. Used for animals, plants, or even bacteria.
ウサギはすぐに繁殖する。
Rabbits multiply quickly.
A more general verb that can also be used for breeding, especially in casual contexts.
掛ける is the everyday word for multiplication, used in school and daily life. 乗じる is formal and appears in technical writing. In conversation, always use 掛ける.
掛ける only means mathematical multiplication. To say 'multiply profits' or 'multiply rabbits', use 増やす or 繁殖させる. Using 掛ける in those contexts would be confusing.
5に6を掛けてください。
Multiply 5 by 6.
暖かい環境では細菌が急速に繁殖する。
The bacteria multiply rapidly in warm conditions.
The population multiplied rapidly.
He succeeded in multiplying his fortune.
I want to multiply my goldfish.