常用数学运算和符号的英文读法

计数方法

  • 小数(decimal; decimal number)
    0.5: zero point five; point five.
    10.875: ten point eight seven five.
  • 小数舍入(rounding)
    1.2735 rounded to 3 decimal places is 1.274.
  • 分数(fraction; fraction number)
    a/b: a over b.
    1/2: one half.
    1/100: one hundredth.
    分子: numerator; 分母: denominator.
  • 百分数(percentage)
    10%: ten percent.
  • 科学计数(scientific notation)
    $1.23\times10^3$: 1.23 times ten to the power of three; 1.23 times ten to the third (参考幂运算).

基本运算

  • 四则运算(Elementary arithmetic)
    $a+b=c$: a plus b equals c (plus是介词).
    $a-b=c$: a minus b equals c (minus是介词); b substracted from a leaves c.
    $a\times b=c$: a times b equals c (times是介词); a multiplied by b is c.
    $a\div b=c$: a divided by b equals c.
    $1/x$: the reciprocal of x.
    $3:5$: three to five.
  • 乘方/幂运算(exponentiation)
    $a^n$: a to the n-th (power); a to the power of n; a raised to the n-th power.
    $x^2$: x squared.
    $y^3$: y cubed.
    指数: exponent.
    底数: base.
  • 开方(radication)
    $\sqrt{9}$: the square root of 9.
    $\sqrt[3]{8}$: the cube root of 8.
    $\sqrt[n]{b}$: the n-th root of b.
  • 对数(logarithm)
    $\log_b x$: the logarithm of x to base b.
    $\log x,\ \ln x,\ \log_e x$: the natural logarithm of x.
    $\lg x,\ \log_{10} x$: the common logarithm of x.
    $\text{lb}\ x,\ \log_2 x$: the binary logarithm of x.
  • 阶乘(factorial)
    5!: five factorial.

基本符号

  • 小括号() (parentheses)
    $(2x - 6y) - 10$: the quantity two x minus six y, close quantity, minus ten;paren, two x minus six y, close paren, minus ten; left paren, two x minus six y, right paren, minus ten.
    $a (x - y)$: a, parenthesis, x minus y, close parenthesis.
  • 中括号[] (brackets)
  • 大括号\{\} (brace)
  • 斜线/ (slash)
  • 反斜线\\ (backslash)
  • 井号# (hash; number sign, pound sign)
  • 与号& (ampersand)
    a & b: a and b.
  • 星号* (asterisk, star)
    $x^*$: x star; x asterisk.
  • 十字$\dagger$ (dagger)
  • 撇号’ (apostrophe)
    $a’$: a prime (US); a dash (UK).
    $a’’$: a double prime (US); a double dash (UK).
  • 省略号$\cdots$ (ellipsis)
    $\frac12+\frac14+\frac18+\cdots$: one half plus one quarter plus one eighth and so forth.
  • 叹号! (exclamation mark)
  • 逗号, (comma)
  • 句号. (full stop, period)
  • 问号? (question mark)

特殊数学符号

  • 正负号$\pm$ (plus-minus)
  • 成比例$\propto$ (is proportional to)
  • 无穷$\infty$ (infinity)
  • 上下标 (superscript, subscript)
    $a_1$: a (sub) one.
    $\varepsilon_{ijk}$: epsilon (sub) ijk.
    $a^i$: a super i.
  • 附加符号(diacritic)
    $\bar{a}$: a bar.
    $\tilde{x}$: x tilde.
    $\hat{a}$: a hat.
    $\dot{y}$: x dot.
    $\vec{x}$: vector x.

逻辑运算符号

  • 相等$=$ (equal, is equal to)
  • 不等$\neq$ (is not equal to)
  • 大于$>$ (is greater than, is larger than)
  • 小于$<$ (is less than, is smaller than)
  • 大于等于$\geqslant$ (is greater than or equal to)
  • 小于等于$\leqslant$ (is less than or equal to)
  • 约等于$\approx$ (is approximately equal to)
  • 赋值$:=$ (is set to be, is defined to be)

代数与函数运算符号

  • 绝对值(absolute value)
  • 求和(summation)
    $\sum_{k=1}^n k^2$: the summation over k from 1 to n of k squared; the summation of k squared over k from 1 to n.
  • 求积(product)
    $\prod_{k=1}^n \frac1k$: the product over k from 1 to n of one over k.
  • 函数(function)
    $f(x)$: f of x.
    参数、变量: argument.
  • 反函数(inverse function)

微积分符号

  • 极限(limit)
    $\lim_{x\to 0} f(x)$: the limit as x approaches zero of f of x; the limit of f of x as x approaches zero.
  • 导数(derivative)
    $f’(x)$: f prime of x; the derivative of f with respect to x.
    $\frac{dy}{dx}$: d y over d x; the derivative of y with respect to x.
    $\frac{\pd y}{\pd x}$: partial y over partial x; d y over d x; the partial derivative of y with respect to x.
  • 积分(integral)
    $\int_0^\infty f(t)dt$: the integral from t equals 0 to t equals infinity of f of t d t; the integral of f of t d t as t goes from 0 to infinity; integrate f of t d t from 0 to infinity.

方程的解

  • the solution of equation
  • the solution for x
  • the key to the question

参考资料

  1. 常用数学运算和符号的英文读法
  2. List of mathematical symbols - Wikipedia