Add comma in array

How do i divide a value in an array, and keep one decimal ?

It is generally best not to throw away accuracy until you need to, so don't do this until you are going to display it. When you need to display it, often the display widget will allow you to do this in the widget. Otherwise you can use toFixed() in a function node to convert the number to a string with the required resolution.

Hi! Do you have an example of how to do this?

A good idea - when yo have a question about something like 'toFixed() is to do a google search using 'javascript toFixed()' and look at the explainations you find.