Alternative to select function in VBA?

I use a  excel woorkbook with some VBA in it and are excerpering a problem. The workbook works great when it's the only workbook open, but when other workbooks also are open, my workbook tend to crash when switching between workbooks and entering data in the cells.

I don't really know what's causing the problem, but I suspect it to be something with the use of SELECT. Therefore I want to get rid of the select functions to test if that is causing the crashes.

The code is attached to dropdown list (using datavalidation), there the users can choose between different types of how to show data:
 

If Target.Address = "$C$10" Then
    
    Range("C28:D89,I28:J89,O28:P89,U28:V89").Select
    
    Select Case Cells(10, 6)
    
        Case 0
            Selection.NumberFormat = "0"
        
        Case 1
            Selection.NumberFormat = "0.0"
        
        Case 2
            Selection.NumberFormat = "0.00"
        
        Case 5
            Selection.NumberFormat = "0%"
        
        Case 6
            Selection.NumberFormat = "0.0%"
            
        Case 7
            Selection.NumberFormat = "0.00%"
            
    End Select
 
    Range("C10").Activate
    
End If

Select all Open in new window

Any alternatives to the SELECT function?