How to delay the execution of a JS function?

Question

JavaScript

There is a code - https://jsfiddle.net/no84cbuq/. Two functions: input validation and the calculator itself. Why, when performing a calculation, innetHtml displays the result in divs and immediately everything is updated. How to make a delay?
I tried to remove the form tags, then the values ​​​​are displayed and do not disappear. But I need to have select and required in this select-a. And without the select form does not work. How to be?

Answer 1

Too lazy to fiddle with the code, so I pasted it right there:
https://learn.javascript.ru/default-browser-action
PS Please write classes, names of variables, functions, etc. in English. Transliteration is just terribly readable and hurts the eyes) And jsfiddle has a separate field for JS code. Even if you copied the code from your editor, it was possible to move the JS there to make it easier for people to look at it.