combine 2 worksheets and hide duplicates

See if this will work for you

Sub t()
Dim sh1 As Worksheet, sh2 As Worksheet
Set sh1 = Sheets("Sheet1") 'Edit sheet names
Set sh2 = Sheets("Sheet2")
sh1.Range("A1", sh1.Cells(Rows.Count, 1).End(xlUp)).AdvancedFilter xlFilterInPlace, , , True
sh1.Range("A1", sh1.Cells(Rows.Count, 1).End(xlUp)).SpecialCells(xlCellTypeVisible).EntireRow.Copy sh2.Range("A1")
sh1.ShowAllData
End Sub

or did you want the duplicate numbers isolated?

A formula is entered directly into a cell on a worksheet by using the equal (=) sign. These are macros, also referred to as Sub procedures, written in Visual Basic for Applications (VBA). To use these particular procedures, in the host workbook, you would open the Visual Basic Editor (VBE) by pressing Alt + F11. If the screen is dark, click 'Insert' on the VBE tool bar, then click 'Module'. The large pane should then brighten. Copy the code to the large pane. The host workbook is the one from which you want to run the procedure, in this case the same one that contains the worksheet with your data. But since there are deletions involved in the procedure, I am not sure that you should try to use these procedures with your level of expertise. I was of the initial impression that you understood the use of macros.

To use macros, your system must have the proper security setting and in your trust center, you must check the box for 'Trust access to the VBA project object model'. The workbook hosting the macro must be a macro enbled workbook, .xslm. So there is a lot more to using macros than just copying one to your file.

But I don't know how you would do what you want to do without using a macro, except to do it manually.

One other thing, if you do start using macros, be sure you test them on a copy or mock up of your file before running them on the original file. Many files have been totally wiped out by running a bad macro without first testing it.