I have a hard time thinking about OOP... And examples using the words Foo and Bar drive me crazy because I don't understand a thing... Visual type person haha

SO I found an example that I'm sure would help clarify it for me...

Alright say you have one formula that is
"5 * [Variable]"
and the other formula is

And one wanted to execute
5 * [5 * [5 * [5 * [Variable]]]]

Then this is where OOP would come in, right?
If so, how would this look like in php?