You can use Excel formulas for basic number crunching, such as addition or subtraction, as well as more complex calculations such as payroll deductions or a student's average on test results.
Additionally, once you have entered the formula, you can change the data and Excel will automatically recalculate the answer for you.
Excel formulas are great for working out What if scenarios that compare calculations based on changing data. Once the formula is entered, you need only change the amounts to be calculated. You dont have to keep entering plus this" or minus that like you do with a regular calculator.
So, working out the sales tax you will pay if you spend this amount or that on an item, or calculating what your income will be if you work so many hours a week, is easily done with Excel formulas.