Who won't be happy to remember every bit of info that is needed for the exams? But! It's not easy to remember everything that we have read. Probably, even the Romans might have faced the same difficulty. That's why they have invented simple techniques to remember vast things... and the technique is named as 'MNEMONICS'.
The word mnemonics has derived from the name of a goddess named 'Mnemosyne'. She is the Greek goddess for memory! The Greek and Romans used the technique of imagory buildings to store a detail in their memory. In this process they imagine a building with certain number of rooms. If they wish to remember a number, they visualize it to be placed in that room. This technique of remembering things using tiny and feasible techniques have later on paved the way for the modern Mnemonics.
People have been adding their own ways of remembering to the list of mnemonics. But these are some of the time tested Mnemonics that are easy to practice and effective to remember.
ACRONYMS: In this method, the first letters of a list are combined together to form an acronym. The best example for this is VIBGYOR. VIBGYOR not only specifies the colors of a rainbow (Violet, Indigo, Blue, Green, Yellow, Orange and Red), It also arranges then in the order of their wavelength. Violet has the shortest wavelength while the color Red has the longest wavelength.
SENTENCE: This method is also referred as the 'Order Mnemonic'. In this method, the first words of a list are formed into a meaningful sentence. For example to remember the eight planets in the Solar system, read this sentence carefully - "My Very Excited Mother Just Served Us Noodles". The first letters of each word would combine into the eight planets of our system in the order... i.e., Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
WORD-LENGTH: We all have experienced the difficulty of remembering the 'Pi' value - 3.141592. Now! If you form a sentence with the words that are as lengthy as each of the digit, that could be a mnemonic. For example: 'How I wish I could calculate pi'. The length of each word in this sentence would represent each digit of the Pi value - How (3) I (1) wish (4) I (1) could (5) calculate (9) pi (2).
IMAGE: Visualizing weird and funny images to remember a word would do the trick. For example the collection of stamps is called 'PHILATELY'. Imagine a PHILOSOPHER with long beard watching stamps on 'TELEVISION'. Image such weird scene until it gets registered in your mind. Later on, when you visualize 'philosopher' and 'television'... the word 'philately' would certainly strike you.
CONNECTION: Connecting the latest information, to the information we are already aware of would yield good results. For example, if we are always confused of the vertical lines and diagonal lines. Remember the movie 'Vertical Limit' which is about the heights of Himalayas. Now you can associate height with the word 'VERTICAL' and the flat line would of course be a 'DIAGONAL' line.