Due to formatting requirements numbers get stored as text in Excel. in order to apply formulars to these texts you will need to convert them to numbers first.
Method 1
This method only works in Excel.
Step 1.
to select the region, click on the column you want.
hold the shift key.
Step 2.
while still holding the shift key click on the lower right column of the region you want.
step 3.
click on the yellow icon and select convert to text.
Method 2
this method works both in Excel and other spreadsheets.
Step 1.
unmerge the cells.
click on the top most conner to select the whole spreadsheet.
click on the merge/unmerge cells.
step 2.
with the cells unmerged you can select columns you want easily.
step 3.
click on data -> text to columns
*Note if the option is grey out you may need to do one column at a time.
you will be prompted with the following options
the options should be
'separated by"
tab
string delimiter ="
step 4.
verify the column changes.
I'm using LibreOffice, text numbers have a prefix in-front of the number. in Excel, the cell will have a yellow icon.
this screenshot is a normal number.
text type number has a modifier in front.
Method 3
Using 3rd party addon.
Note support is unable to provide assistance with 3rd party tools as we have no control over such tools.
a simple conversion tool can convert the whole sheet or convert base on your current selection.
it is better to use the current selection option