You might recall from grade school sometimes you put things in parentheses so that your addition happens first, then your multiplication, otherwise multiplication would happen by default first.

你们可能会想起小学时，将一些加法表达式,放在圆括号里，这样加法可以先计算，然后是乘法，否则，乘法默认先发生。

哈佛公开课 - 计算机科学课程节选

And so, in fact, if I wanted the other version of it, in fact, if I do this right, 23 it's going to give me 23 because it does the multiplication first, if I wanted the other version of it, Python I need to tell it that, by using, excuse me, parentheses.

因此，实际上，如果我想换种做法，实际上，如果我去执行这个表达式，返回值是3,因为乘法会被优先执行，如果我需要换种做法，我需要告诉，用括号来告诉它。

麻省理工公开课 - 计算机科学及编程导论课程节选

n It takes discrete values, multiples of some integer n, and the multiplication factor is the ratio of the Planck constant divided by 2 pi where n takes one, two, three and so on.

这些离散的值乘以整数，乘积因子,是普朗克常数除以2π,其中n可以取1，2，3，等等。

麻省理工公开课 - 固态化学导论课程节选