write it on a piece of paper or read it out loud
It's a matter of attention and training. The more you read, the easier it is for you to relate the different bits of information to each other, understand them and remember them.
because of the music
The easiest way to remember things is to write it down a couple times. You can also review/read the thing you are trying to remember a couple of time first thing in the morning.
Purely a matter of convenience. It's much easier to write, read, say, and remember 6.023 x 1023 than it would be to write, read, say, or remember 602,300,000,000,000,000,000,000. And it's a lot easier to add, subtract, multiply, or divide two of that kind of number if they're presented in scientific notation.
One way to remember math easier is by practicing. The more you do something the more inclined you will learn it and it will be easier in the future.
I find it easier to memorize Surahs when I write them down in a transliteration that I can remember, and remember that English transliteration, not what the Arabic looks like. With the transliteration, you can get the pronunciations correct because you can read them more easily.
I am not aware of any research to support the assertion that it is easier to remember numbers in reverse.
It varies from person to person. Some may find it easier to understand and remember pictorial images, while others may prefer verbal descriptions. It depends on individual learning styles and preferences.
To make poems easier to say and remember
easier to read
It is not.
It depends on the person whether someone remembers a slogan or jingle better, but often a jingle is easier to remember because of the tune.