The memory palace has probably been the most powerful technique for studying and memorising information that I have ever stumbled upon. Once you learn it say goodbye to brute force memorisation and enjoy more certainty. The reason I even learnt that it existed was because of Sherlock Holmes, I wanted to become a deductive genius like him, I didn't but at least I got better at memorisation :)
There have been studies that suggest that the human mind can memorise and hold information better in the form of images rather than text. The more vivid and crazy the images are, the better you will remember them. An image that represents some kind of fact is called a mnemonic. Remembering numbers can be pretty difficult so let's construct some mnemonics for them:
Now that we are prepared let's construct a mnemonic. Let's imagine an Indian scammer in shackles with Queen Elizabeth holding the shackles. Now the Indian breaks his shackles, then with a candle sets fire on a bowling ball and with the fiery ball kills the dog of the 7 dwarfs. Imagine this as vividly as you can. You just learned that India gained its independence from Britain in 1947.
We have learned how to create a mnemonic which leveled up our memorisation game. Now with the memory palace we can store a bunch of mnemonics in some place and have the ability to recall all of them. To construct a memory palace choose a place which is deeply familiar to you. Now start at some point, usually at the entrance and for each fact that you need to remember you can create a mnemonic and associate it with a certain part of your palace, after each fact move in a certain pattern, don't just hop around to different rooms, you have to imagine yourself, walking through it and stopping at a location and seeing a mnemonic there. For example i like to move by generally sticking to the right wall, of course I will disobey this rule in order to go through the entire place. For example I might start at the entrance, imagine some kind of image mnemonic on the door, get in immediately to my right at the staircase imagine something else then at the climbing the staircase i find something else, then in the room on my right, I imagine a fact for each important location in the room, ie. the desk, the bed, the closet, the door etc, then move to the next room, then to the kitchen then to the toilet, to the living room, you get the idea. Honestly it's that simple. Construct your memory palace go through it and see if you remember everything, if some fact is not sticking try to change the mnemonic and make it even crazier.
Now all you need is practice and patience. Sometimes I get too lazy and don't want to construct a memory palace but even then I do use mnemonics. The memory palace however is almost guaranteed to hold everything you need. I even remember a fact I memorised 10 years ago for a biology test. Now that I finished school I don't find it that important but mnemonics are awesome for memorising phone numbers, addresses and stuff.