Math: Reading exponents (powers)?

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Canada - English/French

How are exponents (powers) in an algebraic or arithmetic expression read aloud in Japanese? I did a quick search of the forum for "exponent", "math power" ("power" is obviously too general!) and translations of "exponent" in Japanese according to my EN-JA dictionary but came up blank. =(

For example:

x^4 + bx^3 + cx^2

would be read in English as:

"x to the fourth power plus b x cubed plus c x squared"
"x to the fourth power plus b x to the third power plus c x to the second power"

Or as shorthand (shortmouth?):

"x to the four plus b x cubed plus c x squared"

How would the exponents (bolded above in English) be expressed in Japanese? Are there several ways to express them, as in English? Do Japanese speakers resort to anything akin to "x four" when reading quickly/informally (just reading the numeral after a variable to indicate a power)?


  • hanako52

    I can't write this 数式(すうしき)in the Japanese way because I don't know how to type 記号(きごう) for the exponents.

    We say xの4乗(じょう)足すbxの3乗足すcxの2乗.

    As far as I am concerned, the above is the only way to express this 数式.


    I would read
    x (エックス) 4乗プラス bx3乗 プラスcx自乗(じじょう).

    You can also use xの立方(りっぽう)for x^3 and xの平方(へいほう) for x^2, but I don't think these are very common.


    Senior Member
    Additional information.
    The second power is called either 2乗(nijo)or 自乗(jijo).
    The former is currently in use in schools, simply meaning "multiplying twice".
    The latter is an old-fashioned form, meaning "multiplying itself".
    Though old-fashioned, math teachers, especially aged ones, often used 自乗.
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