Hello!

You can go to data, then validation. From there you can choose allow list, so you can have a drop down list. You have to put your data inputs somewhere to do the drop down list, presented as a table. A drop down list will allow you to select a value from a table of values, depending on what you choose.

Next, you just have to place a value you want to deduct from your drop down list on a any random cell. For this example, we can say it as A1. Then you can build a formula on another cell, where dropdown list - A1 is the formula on another random cell B1.


Anyway for more tips on excel and financial models, you can check the page out. Hope this helps.