I have a second piece of paper (in my back pocket) with some other word on it, just to make sure I'm never lost.
I stopped writing shopping lists. I don't need them. I just carry a piece of paper with "the usual" written on it. I can go to a store and buy the same things I usually buy without having to remember anything, because I have it on paper.
It also helps when someone asks me what did I have for breakfast.
True fact: this scene from a 1971 Polish superhero comedy film 'Hydrozagadka' is a reference to ed, the standard text editor.
I won't go into details but the main idea goes like this: let's say you have 5192/7. You can write 5192 as 5000+100+90+2 but you can also do it like this: 7(555)+7(11)+7(9)+2 but you that's obviously less than 5192 so you can add respective complements 1115 23 27 (finding them is trivial). 1115 = 7(111)+223+7(11)+23+7(1)+5 and so on
I'm trader of used ideas. Large selection
Pardon my french (Latin: I'm sorry for my english).