Microsoft Office Questions? Ask a IT Expert for Support ASAP
Excel has a storage limitation for accuracy, as do all software programs and languages. In a programming language you would write a custom data type of an array of integers to store a number that large, and all the custom functions you need (addition, subtraction, etc). So if you copy and paste that number into excel 1028418416021567839150703, it is stored with 15 significant digits, the last being rounded.
Now, if you take 1028418416021567839150703 and copy it, format the cell in Excel to text before you paste, then paste. It will show all digits. You can use functions to convert the text to a number (using the Value function), however excel will round it back to 15 sig figs.
If you have just the downloaded Excel file, there are only 15 significant figures stored there. The rounding happened in storage and it's gone. If you have the original numbers and are building the excel spreadsheet, you could do some tricks to make it work. Effectively making it text, splitting it into substrings of specified length, and writing cells that split everything out to do any math, then convert those numbers (of no more than 15 significant figures) to text, and concatenate the text.
I have had to do this personally, which is why I know about it, but here is the Microsoft Knowledge base article: https://support.microsoft.com/en-us/kb/65903.
From a very low level computer science perspective what is happening is the memory allocation process limits the number of bits for a defined type. Microsoft has not created a data type for Excel to storage large numbers. Because it would require an array or list based ADT (advanced data type) in the actual code for Excel, it reduces the speed optimizations available on the processor (basically the specialized commands that are sent to the CPU which are predefined to access hardware optimizes which is several orders of magnitude beyond any speed increase that software can provide). So there are some work arounds, but I need more details on what you are trying to do.
If you only need to view in a data table, just formatting the cells as text and pasting in will work. The formulas are where things get excessively difficult.
Also note, at 15 significant figures, some rounding occurs in intermediate steps, so although they are stored, they may not all be accurate depending on the function Excel runs.
Can you post the web address?
I'd the CSV is truncated, there is nothing excel can do. They are lost at that point.
Can you only download the file or does the page show a table (html), that you can copy and paste from then into .csv? I'm trying to look for where the truncation is happening, exactly. If the csv file is rounded it's before that and that could be a browser issue, if you can see the table with full data as an html you could copy and paste it. If that works it can most likely be scraped, or look into a plug-in for the browser, or possibly link excel to direct download the data. There are a couple of options, if I could see the site it would help, of course I do not know if you can share the data even if you wanted to. Just trying to find a solution for you.