If you are adding a list of numbers, you do each calculation at once.
What if I said you can tell the piece of paper how to add once, and repeat it the whole way down.
Excel allows us work with big (or small) sets of numbers and allows for manipulation to be
EASY, CLEAN, and REPEATABLE. This repeatable word is extremely important, it is the root of automation.
If you want to be part of the future - these are concepts you should be familiar with.
Excel is a great tool to get started with that!