What are these examples of?
They are mnemonics.
What is a mnemonic?
A mnemonic is a memory aid. It could be a song, a rhyme, a picture or a phrase.
It's also a good idea to personalise any mnemonics; they'll be easier to remember too. Try making up your own or adapting one.
Is there a mnemonic you use as a memory aid? Which mnemonics do you use to help you spell tough words, to remember tricky mathematical methods or to help you remember difficult things?