Ever wondered that while entering any formula, you see certain parameters having a box bracket [parameter] around it, and certain parameters don’t have it!
eg.: =SUM ( number1, [number2], [number3], … )

This is because all the parameters that are NOT in box brackets, are mandatory parameters, i.e., you cannot enter the function without those particular parameters.

The one’s WITH the box brackets are non-mandatory parameters, i.e., you may or may not enter those parameters in the formula.

In the above example, ‘number1’ is a mandatory parameter, and number2, number 3 and so on are non-mandatory parameters.

Enjoy Paramtering 🙂