Ex17 Calculating with Defined Names

A reference that refers to the same cell or range on multiple sheets is called a 3D reference. A 3D reference is a useful and convenient way to reference several worksheets and/or cells on each worksheet that follow the same pattern, or contain the same type of data, such as when you consolidate budget data from different departments in your organization.
3D References are cell references (sets of coordinates) that point to another cell or range of cells in a different worksheet (or even a different workbook). Where a cell reference might be B3 (Column B, Row 3 in this worksheet) a 3D reference would be 'Sheet 2'!B3 (cell B3 in Sheet 2). They can also refer to the same cell, or range of cells, on multiple worksheets. You can use them to add values across worksheets with ease. They are a useful and convenient way to reference several worksheets that follow the same pattern and contain the same type of data.