A constant is a number that is always the same. Simple examples would be numbers such as pi, which is ~3.14159...
Keep in mind though, while pi is endless, a constant doesn't have to be. It's just a number that doesn't change, so to speak.
The mathematical term for "mean" is "mean".The popular, or colloquial term for "mean" is "average".
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It is the e mathematical constant, Euler's constant.
It means to work out the answer of a given mathematical problem.
math
Mean is the mathematical term for average.
Convention is not a mathematical term: it means what is generally done or an accepted way of doing something.
it means to be wrong
It means an explanation
Inspiration is not a mathematical term. It, therefore, means what it does in normal usage.
round up or estimate it
It is not a mathematical term - it is not specific enough.