1) Click on the Define Name button on the Formulas Tab
2) In the New Name dialog box enter the Name of your value, in our example it's "Discount".
3) Select the Scope: In the image below it's the entire Workbook.
4) In the Refers to: field enter your value, in our case =0.10 for a Discount of 10%.
To update the value simply edit the Named Constant in the Name Manager
4) Navigate quickly to a section of your workbook/worksheet
5) Automate Named Ranges: by inserting a Table (Insert tab, Table) Excel automatically gives the table a name like Table1. Go to the Name Manager to change the default name to something more meaningful.
Note: you can't make a reference to a cell in a table absolute, so there is a time and a place for Tables.