Symbol known

Question

how will you know that a combination of particular symbol is going to mean what u intend having

Answer 1

That's called a syntax. You learn it :)

Answer 2

% is modulus
+ is add
- is subtract
* is multiply
/ is float division (division returns float)
// is int division (division returns integer)
** is exponentiation (for root, by law of indices, use 1/(no. on the root))
...

Answer 3

could you please give more information

Answer 4

I presume the question was about symbols for intend?
There are the the space or the tab.
The main rule is not mixing them and use the same numbers of them in begin of every line of inner block.