Using Invisible Dots on numbers 1-9 for math. Does anyone know what I am talking about?

When I do addition I often use imaginary dots on the numbers 1-9. So a 1 has one dot, 2 has one at the top and one on the bottom, a 3 has one at the end of each curve,...a 6 has two dots at the top, middle and bottom, an 8 has two dots on each side on the top part and the bottom part....something like that. I think I learnded this very young and am not sure of every detail of how to use this method. I am trying to research it but can't really find anyrhing on it as i have no clue what it is called, and doesn't seem to be used much anymore. I was trying to find out if this is a good way to teach my young children who are beginning math. But didn't want to start until I was sure I understood it all. Is there anyone who knows what this is called or how it is done correctly?