The reason why they’re abstract and difficult to relate to is because we’re all being taught maths backwards.
In science, a phenomenon is observed and then maths is used to create a set of equations describe it’s behaviour. Then using the equations, other experiments can be designed to prove other hypothesises. This is known as the experimentalist approach to science.
Engineering is the same but less research and more application focused. For example, I need to design a wooden shelf that is A inches/meters long and supports B lb/kg of weight. How do I do that? Using trigonometry and Newtonian physics to work out the dimensions.
Finance is often used for basic algebra and calculus.
However, it is not always helpful to work in the material when using mathematics and the abstract is preferred. This is usually only useful for the theoretical approach in science, in theoretical mathematics, or at the cutting edge of engineering disciplines.
If we were taught by being presented with a problem first, I think it would make it easier to make the leap into the abstract when required for other applications. And on top of this, it would make it much easier for the majority who only ever need to use mathematics as a tool.
I would have certainly loved it if they showed me the actual problem and then solve it with math, instead of showing how to solve abstract, non-real-world problems in math using a bunch of complicated theorems that you just have to memorize (I know they can be solved, but you still have to memorize them for when you need to use them).
Because there is no need to pluralize the word. Math is short for “mathematics” so writing “maths” just makes you look stupid.
Ultimately it’s the same reason why you don’t say “admins” for administrator or detoxs for detoxification.
Do you say flus? No you say flu because it’s the shortened version of influenza.
“If Johnny has 3 apples, and Jane takes 1 apple, how many apples does Johnny have?”
Depends.
Did Jane take an apple from the only source of apples stated in the question; Johnny? If so then 2.
Did Jane take one apple from a source not stated in the question. If so then 3.
Has Jonny eaten any of his apples? If so then |3-n| where n is the number of apples Johnny has eaten.