Calling Excel experts

[R1 GTR]

My dads stuck at work.
He's got a spreadsheet full of positive numbers, he now needs to change them ALL to negative, its a big spreadsheet.
Can he do it in one go or does he have to change them one by one?
Urgent help needed

[Plotloss]

*-1

[cactussed]

I'd open a new woorksheet, plug un a formula (=<cell> * -1).
Copy and pase for every cell (should take 5 seconds) then select all, copy, paste special, values.

Sorted.

[R1 GTR]

cheers guys all sorted

[eyebeebe]

For future reference there is an even quicker way of doing it.

simply enter '-1' in a cell. Copy the -1, highlight the area of cells which need to changed and do a paste special, values and change operation to mulitply.

[corozin]

Just remember...

a positive number multiplied by a positive number is a positive number
but... a negative multiplied by a negative is also a positive number