Reading Math Out Loud | 数学公式的英语读法

This will be a bilingual post. 本文双语。

When multiple readings are possible, the most commonly used ones are listed on top. 有多种读法时，最常用的读法排在前面。

For Chinese learners
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英文读法在这里
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Basic arithmetic | 四则zé运yùn算suàn

1 + 2

一加jiā二

一加上shàng二

one plus two

add two to one

1 – 2

一减jiǎn二

一减去qù二

one minus two

subtract two from one

one takeaway two*

* takeaway 稍不正式，一般是教小孩子做减法时这么说。

1 × 2

一乘chéng以yǐ二

二乘一

one multiplied by two

one times two

1 ÷ 2

一除chú以二

二除一^*

one divided by two

one over two

* Although 除 and 除以 are officially the opposite of each other, this distinction is not well understood by most people. Avoid using 除 and always use 除以 to prevent misunderstanding. (This distinction also exists for 乘 and 乘以 but multiplication is commutative so nobody cares.)

* 为什么“除以”和“除”是反过来的呢？因为“以”相当于英文中的 by。一除以二，即 one divided by two，即以二除一。二除一，好比 two divides one。英文没有这个用法，但有 goes into（见下文）。“乘以”和“乘”其实也是反过来的，但是乘法有交换律，所以无所谓。

– 1

负fù一

negative one

minus one

Equations | 等děng式shì

1 + 2 = 3

一加二等děng于yú三

一加二得dé三

one plus two equals three

one plus two is three

3 × 5 = 15

三乘以五等于十五

三五(一)十五 *

three times five equals fifteen
three times five is fifteen

three fives are fifteen **

* This is how you read it as part of the multiplication table.
** 这种读法一般只出现在九九乘法表里，但英文乘法表根据地域不同，三种读法都有可能。

10 ÷ 2 = 5

十除以二等于五

十除以二得五

ten divided by two equals five

ten divided by two is five

two goes into ten five times
（把二往十里填，可以填五次）

Decimals and fractions | 小xiǎo数shù与分fēn数

3.1

三点diǎn一

three point one

3.14

三点一四

three point one four

3.333…

三点三三三(无wú限xiàn)循xún环huán
(… (infinitely) cycle)

three point three three three repeating

$\frac{2}{5}$

五分fēn之zhī二
(of five parts, [take] two)

two fifths

two over five

$1 \frac{2}{5}$

一又yòu五分之二

one and two fifths

one and two over five

$\frac{n}{m}$

m 分之 n

n 除以 m *

n over m

* In algebra (with letters and all), the more complicated the formula is, the less likely the speaker will say 分之.

Roots and exponents | 开kāi方fāng与乘方

$2^5$

二的五次cì方fāng

二的五次幂mì

two to the fifth power

two to the fifth

two to the five

$x^2$

x 的平píng方

x 方

x squared

$x^3$

x 的立lì方

x cubed

$x^y$

x 的 y 次方

x to the yth power

x to the y

$\sqrt{x}$

x 的平方根gēn

根号hào x
(root sign x)

x 开kāi二次方

开方 x

square root of x

root x

$\sqrt{2}$

根号二

根二

二的平方根

root two

square root of two

$\sqrt[3]{x}$

x 的立方根

x 开三次方

cube root of x

$\sqrt[4]{x}$

x 的四次方根

x 开四次方

fourth root of x

$\sqrt[y]{x}$

x 的 y 次方根

x 开 y 次方

yth root of x

Disambiguation | 消歧义

Pause briefly at the commas. 有逗号处稍停顿。

$1 + \frac{2}{3}$

一，加三分之二

one, plus two over three

one plus two thirds

$\frac{2}{1+3}$

一加三的和hé，分之二
(the sum of one plus three…)

一加三，整zhěng个gè分之二

two over, one plus three

two over the quantity (of) one plus three

$\frac{1}{3} + 2$

三分之一，加二

a third plus two

one over three, plus two

$\frac{1 + 2}{3}$

三分之，一加二

一加二的和除以三

one plus two, all over three

$\frac{1 - 2}{3}$

三分之，一减二

一减二的差chā除以三
(the difference of…)

one minus two, all over three

$\frac{1 \times 2}{3}$

三分之，一乘以二

一乘以二的积jī除以三
(the product of…)

one times two, all over three

$\frac{1 \div 2}{3}$ *

三分之，一除以二

一除以二的商shāng除以三
(the quotient of…)

one divided by two, all over three

* Usually the ÷ symbol wouldn’t appear in a fraction, but I’m writing it this way to introduce the word 商.

$\sqrt{x} \cdot y$

根号 x，乘以 y

square root of x, times y

$\sqrt{x \cdot y}$

根号下，x 乘以 y

square root of the quantity (of) x times y

square root of, x times y

Examples | 用例

Different people will read these formulas and equations in slightly different ways. 不同的人对这些公式/等式的读法会稍有不同。

$a^2 + b^2 = c^2$

a 方加 b 方等于 c 方

a 的平方加 b 的平方等于 c 的平方

a squared plus b squared equals c squared

$\frac{-b \pm \sqrt{b^2-4ac}}{2a}$

负 b 加减根号下 b 方减四 a c，(整个)除以二 a

minus b plus or minus the square root of (the quantity (of)) b squared minus four a c, all over two a
（或者 … all divided by two a）

$e^{i\pi}=-1$

e 的 i π 次方等于负一
(read π as 派pài)

e to the i π equals negative one
（π 读作 pie）