What do the numbers next to Read and Listened mean on the Lesson Complete popup?

I’m quite unclear on what these numbers too and why they have - and + buttons next to them. To these numbers actually affect anything? I’ve attached an image of what I’m describing.

How many times have you read or listen to the text. It is just information for you and since this system sometime makes mistakes it allows you to change it manually.

Are those numbers useful? Probably not but still it does not hurt to have them.