Digital root · 数字根
This page needs a recent browser (with SharedArrayBuffer support). Please update Chrome, Edge, Firefox or Safari to the latest version. · 此页面需较新浏览器（支持 SharedArrayBuffer）。请升级 Chrome、Edge、Firefox 或 Safari 至最新版本。
This one builds on a lesson you haven't finished yet. Do that lesson first: · 此任务基于您尚未完成的课程。请先完成以下课程：
Python Basics · Python 基础 · Functions · 函数 →
English
Digital root
Keep adding digits until a single digit remains.
Two loops work together here. The inner for adds up the digits once; str(n) lets you loop over them as characters. The outer while repeats that as long as the number still has two or more digits, which is while n >= 10.
中文
数字根
不断把各位数字相加，直到只剩一位数。
这里两个循环配合使用。里面的 for 把各位数字加一遍；用 str(n) 就能把数字当作字符来遍历。外面的 while 在数还有两位或更多位时（也就是 n >= 10 时）重复这个过程。
Write digital_root(n) that adds up the digits of n, then the digits of that answer, and so on until one digit is left. 9875 gives 29, then 11, then 2. · 编写 digital_root(n)：把 n 的各位数字相加，再把结果的各位数字相加，如此重复，直到只剩一位数。9875 得到 29，然后 11，最后 2。
Click Run to see the output here. · 点击“运行”查看此处输出。