Generally it has been found unnecessary to use figuration for a tonic chord in root position, which, if expressed would be 53.

据发现，通常没有必要用数字标记原位主音和弦，如果要用数字标记的话，为53。

youdao

We've got some chords set out and we're going to-- we've got some chords set out here and we're in the key of C at this point, and we're going to hear Beethoven go to a tonic chord, then a sub-dominant chord, then a tonic chord, then a dominant chord and so on.

我们看到有一些和弦-,而我们现在在C调的位置上，然后听贝多芬的主音和弦，然后是次属音和弦，然后是主音和弦，接着是属音和弦，如此往复。

耶鲁公开课 - 聆听音乐课程节选

Now we're going to hear Beach Boys, IV I guess,with a three-chord chord progression and it's going to be sub-dominant , V dominant , I tonic .

而现在我们来听听貌似是沙滩男孩，三和弦进行，然后将会是次属音，属音，和主音。

耶鲁公开课 - 聆听音乐课程节选