Infix notation is a way of writing calculations in a way that you are probably used to. It's like when you write a math problem on paper with numbers, plus signs, minus signs, and brackets in between them.
Instead of writing, "3 plus 2 equals 5" like we would in regular English, we write it as "3 + 2 = 5." The plus sign is in between the two numbers to show that we want to add them together.
This is what infix notation is – writing math problems in the order that we are used to seeing them. It's helpful because we can read the problem and understand it quickly without having to think about the order of calculations.
Does that make sense, kiddo?