Excel formula includes cell name

I'm trying to convert an excel for开发者_运维问答mula that I found to a more easily understood formula. Below is the formula I'm trying to interpret. What is ei??

=3*ei/2-27*ei^3/32

In the 'Name Box', in the upper left part of your Excel screen, type ei and hit enter. This will take you right to cell ei. The 'Name Box' is that little address box that shows you what cell address you are currently in.

If ei is actually the name of a cell, it will take you right to that cell. If ei is not the name of a cell, typing ei in the 'Name Box' and hitting enter will give the name ei to the cell you are currently in.

You can also use the dropdown arrow for the 'Name Box' to see a list of all the named ranges and cells in the workbook.

It refers to a cell named ei. When you paste this formula into Excel, it probably gives you the error #NAME? meaning there is no cell named ei You can either replace each ei in your formula to a cell reference or go to a cell and name it ei and put the value in there. Named cells are the same, but easier to read, form of absolute reference as Sheet2!$C$4 for example.