While some of the comments above have some validity, I can see you just needing to memorize some quick formulas. I do agree practice makes perfect. But what many of the memorizers AND Joshua Foer said is yes, they are tricks but they FORCE you to memorize things. And Foer goes on to say that they aren't even really tricks. They are actually harder to do that just doing it, because you're kind of setting up a safety net in your mind, and it often involved preparatory work.
Anthony Metivier is another memory "guru" who.. I guess.. throws out all forms of memorization stuff EXCEPT the "memory palace" (google it if need be). Though, while he focuses only on memory palaces, other systems like the Major Memory System, (where you associate the phonetic alphabet with numbers) make guest appearances.
^^^^^More info here^^^^^
So, in Metivier's mind, if you have this..
notice vowels and w, h, y are ignored
..you can associate formulas with words like:
C2 = CaN (You keep the c, ignore the a, use the n)
'=' becomes an image of something meaningful to you, he chooses to use a FLAG
A2 = yawN (again, since you're ignoring the letters y, a, w, you can place them anywhere to make words)
'+' = this becomes another image of your choice- try using a cross, or hospital symbol
B2 = Maybe this is BuN, BaNe, etc.
Now, he went a slightly different (I believe more complicated) route. I simplified this for you if you're new.
You now have images. You throw them into a story. And he would say "USE A MEMORY PALACE TOO!"
The idea would be you would walk through.. say.. your house and in your mind, you're placing these items in your house, in order.
Anyone into memory techniques will say to use your own images, your own words, your own palaces. Do not expect to find any Website on memory palaces and have things mapped out for you. Things like the Major System and Peg System will suggest things for you but if they aren't "sticky" TOSS THEM OUT.
Read more on building memory palaces and rules for doing so.
The Bible of Memory folks-
Google "The Memory Book" by Harry Lorayne
This one focuses on academics-
Super Memory Super Student by Harry Lorayne