integrating multiple workbooks into 1 consolidated workbook

[AndyF]

Hi
i have 12 workbooks all the same each with 70 worksheets with the same format. I need to consolidate these 12 books into 1 book with 70 sheets. Effectively adding the data from each numerical cell.

Ive tried several merge macros Ive found online and they just add the work sheets into 1 workbook so I get 1 work book of 840 sheets.

Any ideas?
Andy