One of the most easy ways to remember information, especially for young students, is to use acronyms to learn and understand concepts in school. Most students probably learned PEMDAS in math class or ROY G BIV in art class, as well as acronyms you made up on your own. Whether you made them up on your own or used the acronyms your teacher presented for you, they most likely stuck with you and helped you to remember this information.
Using acronyms to remember information is an example of Elaborative Rehearsal, which is when a person transfers information from your Short-Term Memory to the Long-Term Memory by making this information meaningful. In your short-term memory, you hold a few items for a short period of time, which is why you can use elaborative rehearsal to relate these memories in your short-term memory in order to keep it stored in the long-term memory. If you were to just try to memorize certain information, you might be able to recall it for a short period of time, but it would not be stored in your long-term memory or allow you to recall this information later in life, it would only be temporary.
In your long-term memory you have almost limitless storage and the information stored is relatively permanent, hence why you apply these acronyms in school. The information is stored in long-term memory because you have made this memory meaningful or related the acronym to prior knowledge you know. I know personally that I still remember specific things like symmetric shapes because of a song my teacher taught me in second grade which I can still recall today, retrieving it from my long-term memories because she made the song meaningful, not just straight memorization.
You gave great examples of elaborative rehearsal. I also remember learning “PEMDAS” in math class as well as “ROY G BIV”. Another acronym that I remember was from music class is “good boys deserve fudge always” this was to help us remember the order of notes. (G, B, D, F, A) Whenever I have a test coming up and I have to remember the order of something, I will use the process of elaborative rehearsal and make up a pneumonic or I will make up a story out of it which helps me remember it and process it into my Long-term memory. Great post on explaining what elaborative rehearsal is!