#8 Memorizing Formulas
The last few techniques have focused on converting numbers into visual cues for our brains to remember. Luckily, the same system can be applied in other ways. We can remember mathematical symbols for example by associating them with visual objects.
The plus sign resembles the red cross symbol on a hospital, whereas a subtraction sign looks more like a long submarine. Remember that these techniques require you to use your own imagination. If you see a subtraction sign as a baguette, then use this cue instead: you’re the inventor!